Деев Игорь Евгеньевич


Период обученияСтрана, городУчебное заведениеДополнительная информация
1996–2001 Россия, Долгопрудный Московский Физико-Технический Институт

Избранные публикации

  1. Pakhomov A.A., Martynov V.I., Orsa A.N., Bondarenko A.A., Chertkova R.V., Lukyanov K.A., Petrenko A.G., Deyev I.E. (2017). Fluorescent protein Dendra2 as a ratiometric genetically encoded pH-sensor. Biochem. Biophys. Res. Commun. 493 (4), 1518–1521 [+]

    Fluorescent protein Dendra2 is a monomeric GFP-like protein that belongs to the group of Kaede-like photoconvertible fluorescent proteins with irreversible photoconversion from a green- to red-emitting state when exposed to violet-blue light. In an acidic environment, photoconverted Dendra2 turns green due to protonation of the phenolic group of the chromophore with pKa of about 7.5. Thus, photoconverted form of Dendra2 can be potentially used as a ratiometric pH-sensor in the physiological pH range. However, incomplete photoconversion makes ratiometric measurements irreproducible when using standard filter sets. Here, we describe the method to detect fluorescence of only photoconverted Dendra2 form, but not nonconverted green Dendra2. We show that the 350 nm excitation light induces solely the fluorescence of photoconverted protein. By measuring the red to green fluorescence ratio, we determined intracellular pH in live CHO and HEK 293 cells. Thus, Dendra2 can be used as a novel ratiometric genetically encoded pH sensor with emission maxima in the green-red spectral region, which is suitable for application in live cells.

  2. Deyev I.E., Chachina N.A., Zhevlenev E.S., Petrenko A.G. (2017). Site-Directed Mutagenesis of the Fibronectin Domains in Insulin Receptor-Related Receptor. Int J Mol Sci 18 (11), [+]

    The orphan insulin receptor-related receptor (IRR), in contrast to its close homologs, the insulin receptor (IR) and insulin-like growth factor receptor (IGF-IR) can be activated by mildly alkaline extracellular medium. We have previously demonstrated that IRR activation is defined by its extracellular region, involves multiple domains, and shows positive cooperativity with two synergistic sites. By the analyses of point mutants and chimeras of IRR with IR in, we now address the role of the fibronectin type III (FnIII) repeats in the IRR pH-sensing. The first activation site includes the intrinsically disordered subdomain ID (646-716) within the FnIII-2 domain at the C-terminus of IRR alpha subunit together with closely located residues L135, G188, R244, H318, and K319 of L1 and C domains of the second subunit. The second site involves residue T582 of FnIII-1 domain at the top of IRR lambda-shape pyramid together with M406, V407, and D408 from L2 domain within the second subunit. A possible importance of the IRR carbohydrate moiety for its activation was also assessed. IRR is normally less glycosylated than IR and IGF-IR. Swapping both FnIII-2 and FnIII-3 IRR domains with those of IR shifted beta-subunit mass from 68 kDa for IRR to about 100 kDa due to increased glycosylation and abolished the IRR pH response. However, mutations of four asparagine residues, potential glycosylation sites in chimera IRR with swapped FnIII-2/3 domains of IR, decreased the chimera glycosylation and resulted in a partial restoration of IRR pH-sensing activity, suggesting that the extensive glycosylation of FnIII-2/3 provides steric hindrance for the alkali-induced rearrangement of the IRR ectodomain.

  3. Pakhomov A.A., Deyev I.E., Ratnikova N.M., Chumakov S.P., Mironiuk V.B., Kononevich Y.N., Muzafarov A.M., Martynov V.I. (2017). BODIPY-based dye for no-wash live-cell staining and imaging. BioTechniques 63 (2), 77–80 [+]

    In nonpolar solvents, hydrophobic organic fluorophores often show bright fluorescence, whereas in polar media, they usually suffer from aggregation-caused quenching (ACQ). Here, we harnessed this solvatochromic behavior of a 1,3,5,7-tetramethyl-BODIPY derivative for cell staining and applied it to live-cell imaging and flow cytometry. As opposed to commercially available dyes, this BODIPY derivative showed excellent contrast immediately after staining and did not require any wash-off.

  4. Deyev I.E., Popova N.V., Serova O.V., Zhenilo S.V., Regoli M., Bertelli E., Petrenko A.G. (2017). Alkaline pH induces IRR-mediated phosphorylation of IRS-1 and actin cytoskeleton remodeling in a pancreatic beta cell line. Biochimie 138, 62–69 [+]

    Secretion of mildly alkaline (pH 8.0-8.5) juice to intestines is one of the key functions of the pancreas. Recent reports indicate that the pancreatic duct system containing the alkaline juice may adjoin the endocrine cells of pancreatic islets. We have previously identified the insulin receptor-related receptor (IRR) that is expressed in islets as a sensor of mildly alkaline extracellular media. In this study, we show that those islet cells that are in contact with the excretory ducts are also IRR-expressing cells. We further analyzed the effects of alkaline media on pancreatic beta cell line MIN6. Activation of endogenous IRR but not of the insulin receptor was detected that could be inhibited with linsitinib. The IRR autophosphorylation correlated with pH-dependent linsitinib-sensitive activation of insulin receptor substrate 1 (IRS-1), the primary adaptor in the insulin signaling pathway. However, in contrast with insulin stimulation, no protein kinase B (Akt/PKB) phosphorylation was detected as a result of alkali treatment. We observed overexpression of several early response genes (EGR2, IER2, FOSB, EGR1 and NPAS4) upon alkali treatment of MIN6 cells but those were IRR-independent. The alkaline medium but not insulin also triggered actin cytoskeleton remodeling that was blocked by pre-incubation with linsitinib. We propose that the activation of IRR by alkali might be part of a local loop of signaling between the exocrine and endocrine parts of the pancreas where alkalinization of the juice facilitate insulin release that increases the volume of secreted juice to control its pH and bicabonate content.

  5. Можаев А.А., Ерохина Т.Н., Серова О.В., Деев И.Е., Петренко А.Г. (2017). Получение и иммунохимическая характеристика моноклонального антитела к эктодомену рецептора, подобного рецептору инсулина (IRR). Биоорг. хим. 43 (6), 631–636 [+]

    Рецептор, подобный рецептору инсулина (IRR, Insulin receptor-related receptor), является единственным известным на сегодняшний день метаботропным сенсором внеклеточной щелочной среды и участвует в регуляции кислотно-щелочного равновесия в организме. IRR экспрессируется в отдельных клеточных популяциях почек, желудка и поджелудочной железы, где может контактировать с внеклеточными жидкостями со щелочным рН. Для изучения его структуры и функции нами получена стабильная линия гибридомы, продуцирующая антитела к внеклеточной части рецептора. Выделенные из асцитной жидкости моноклональные антитела показали позитивную реакцию с антигеном в ИФА. Минимальная концентрация антител, при которой сигнал превышал уровень фона в два раза, составила 12.5 нг/мл. Способность антител специфически узнавать очищенный эктодомен IRR и полноразмерный рецептор была подтверждена методами вестерн-блоттинга, иммунопреципитации и иммуноцитохимии.

  6. Martynov V.I., Pakhomov A.A., Popova N.V., Deyev I.E., Petrenko A.G. (2016). Synthetic Fluorophores for Visualizing Biomolecules in Living Systems. Acta Naturae 8 (4), 33–46 [+]

    The last decade has witnessed significant advance in the imaging of living systems using fluorescent markers. This progress has been primarily associated with the discovery of different spectral variants of fluorescent proteins. However, the fluorescent protein technology has its own limitations and, in some cases, the use of low-molecular-weight fluorophores is preferable. In this review, we describe the arsenal of synthetic fluorescent tools that are currently in researchers' hands and span virtually the entire spectrum, from the UV to visible and, further, to the near-infrared region. An overview of recent advances in site-directed introduction of synthetic fluorophores into target cellular objects is provided. Application of these fluorescent probes to the solution of a wide range of biological problems, in particular, to the determination of local ion concentrations and pH in living systems, is discussed.

  7. Deyev I.E., Chachina N.A., Shayahmetova D.M., Serova O.V., Petrenko A.G. (2015). Mapping of alkali-sensing sites of the insulin receptor-related receptor. The role of L2 and fibronectin domains. Biochimie , [+]

    Insulin receptor-related receptor (IRR) is a member of the insulin receptor (IR) family that works as an extracellular alkali sensor with positive cooperativity. The pH sensing property of IRR is defined by its extracellular region and involves multiple domains. We have previously demonstrated the primary role of L1C domains and identified potentially important amino acid residues within these domains. In this study, we addressed the roles of L2 and FnIII domains. Within the L2 domain, five amino acid residues (M406, V407, D408, P436 and V437) were identified as IRR-specific by performing a species conservation analysis of the IR family. Single-point mutations of these five residues to alanine produced either little or no negative effect on IRR pH-sensing activity. However, the triple mutation of M406, V407 and D408 (MVD) showed a strong negative effect, with a 4 fold decrease in IRR activity as estimated by in vitro autophosphorylation assay of solubilized receptors. The analysis of this mutant in intact cells revealed the absence of positive cooperativity. Unexpectedly, the double mutation of vicinal P436 and V437 (PV) exhibited a significant positive effect in the in vitro assay and partial positive cooperativity in the whole-cell assay. The role of FnIII domains was addressed by analyzing chimeras of IRR and IR. When the IRR FnIII domains were swapped with those of IR in different combinations, the activity was significantly reduced and positive cooperativity eliminated. However, two mutants with the targeted C-terminal part of IRR alpha subunit that lies within FnIII-2 domain and have been shown to be important for insulin binding by IR, appeared to be as active as wild-type IRR. On the basis of available data, we propose that IRR activation involves two separate centers of pH-dependent rearrangements that act synergistically to induce a major conformational change in the IRR molecule, resulting in internal kinase domains rapprochement and autophosphorylation.

  8. Deyev I.E., Mitrofanova A.V., Zhevlenev E.S., Radionov N., Berchatova A.A., Popova N.V., Serova O.V., Petrenko A.G. (2013). Structural determinants of the insulin receptor-related receptor activation by alkali. J. Biol. Chem. , [+]

    IRR is a member of the insulin receptor (IR) family that does not have any known agonist of a peptide nature but can be activated by mildly alkaline media and was thus proposed to function as an extracellular pH sensor. IRR activation by alkali is defined by its N-terminal extracellular region. To reveal key structural elements involved in alkali sensing, we developed an in vitro method to quantify activity of IRR and its mutants. Replacing the IRR L1C domains (residues 1-333) or L2 domain (residues 334-462), or both with the homologous fragments of IR reduced the receptor activity to 35, 64, and 7% percent, respectively. Within L1C domains, five amino acid residues (L135, G188, R244, and vicinal H318 and K319) were identified as IRR-specific by species conservation analysis of the IR family. These residues are exposed and located in junctions between secondary structure folds. The quintuple mutation of these residues to alanine had the same negative effect as the entire L1C domains replacement, whereas none of the single mutations was as effective. Separate mutations of these five residues and of L2 produced partial negative effects that were additive. The pH dependence of cell-expressed mutants (L1C and L2 swap, L2 plus triple LGR mutation, and L2 plus quintuple LGRHK mutation) was shifted towards alkalinity and, in contrast with IRR, did not show significant positive cooperativity. Our data suggest that IRR activation is not based on a single residue deprotonation in the IRR ectodomain but rather involves synergistic conformational changes at multiple points.

  9. Petrenko A.G., Zozulya S.A., Deyev I.E., Eladari D. (2013). Insulin receptor-related receptor as an extracellular pH sensor involved in the regulation of acid-base balance. Biochim. Biophys. Acta 1834 (10), 2170–5 [+]

    Recent studies of insulin receptor-related receptor (IRR) revealed its unusual property to activate upon extracellular application of mildly alkaline media, pH>7.9. The activation of IRR with hydroxyl anion has typical features of ligand-receptor interaction; it is specific, dose-dependent, involves the IRR extracellular domain and is accompanied by a major conformational change. IRR is a member of the insulin receptor minifamily and has been long viewed as an orphan receptor tyrosine kinase since no peptide or protein agonist of IRR was found. In the evolution, IRR is highly conserved since its divergence from the insulin and insulin-like growth factor receptors in amphibia. The latter two cannot be activated by alkali. Another major difference between them is that unlike ubiquitously expressed insulin and insulin-like growth factor receptors, IRR is found in specific sets of cells of only some tissues, most of them being exposed to extracorporeal liquids of extreme pH. In particular, largest concentrations of IRR are in beta-intercalated cells of the kidneys. The primary physiological function of these cells is to excrete excessive alkali as bicarbonate into urine. When IRR is removed genetically, animals loose the property to excrete bicarbonate upon experimentally induced alkalosis. In this review, we will discuss the available in vitro and in vivo data that support the hypothesis of IRR role as a physiological alkali sensor that regulates acid-base balance. This article is part of a Special Issue entitled: Emerging recognition and activation mechanisms of receptor tyrosine kinases.

  10. Popova N.V., Deyev I.E., Petrenko A.G. (2013). Clathrin-mediated endocytosis and adaptor proteins. Acta Naturae 5 (3), 62–73 [+]

    Macromolecules gain access to the cytoplasm of eukaryotic cells using one of several ways of which clathrin-dependent endocytosis is the most researched. Although the mechanism of clathrin-mediated endocytosis is well understood in general, novel adaptor proteins that play various roles in ensuring specific regulation of the mentioned process are being discovered all the time. This review provides a detailed account of the mechanism of clathrin-mediated internalization of activated G protein-coupled receptors, as well as a description of the major proteins involved in this process.

  11. Deyev I.E., Rzhevsky D.I., Berchatova A.A., Serova O.V., Popova N.V., Murashev A.N., Petrenko A.G. (2011). Deficient Response to Experimentally Induced Alkalosis in Mice with the Inactivated insrr Gene. Acta Naturae 3 (4), 114–7 [+]

    Currently, the molecular mechanisms of the acid-base equilibrium maintenance in the body remain poorly understood. The development of alkalosis under various pathological conditions poses an immediate threat to human life. Understanding the physiological mechanisms of alkalosis compensation may stimulate the development of new therapeutic approaches and new drugs for treatment. It was previously shown that the orphan insulin receptor-related receptor (IRR) is activated by mildly alkaline media. In this study, we analyzed mutant mice with targeted inactivation of theinsrr gene encoding IRR, and revealed their phenotype related to disorders of the acid-base equilibrium. Higher concentrations of bicarbonate and CO(2)were found in the blood ofinsrr knockout mice in response to metabolic alkalosis.

  12. Popova N.V., Deyev I.E., Petrenko A.G. (2011). Association of adaptor protein TRIP8b with clathrin. J. Neurochem. , [+]

    TRIP8b is a brain-specific hydrophilic cytosolic protein that contains tetratricopeptide repeats (TPRs). Previous studies revealed interaction of this protein via its TPR-containing domain with Rab8b small GTPase, HCN channels and G protein-coupled receptor CIRL. We identified clathrin as a major component of eluates from the TRIP8b affinity matrix. In the present study, by in vitro binding analysis we demonstrate a direct interaction between clathrin and TRIP8b. The clathrin-binding site was localized in the N-terminal (non-TPR containing) part of the TRIP8b molecule that contains two short motifs involved in the clathrin binding. In transfected HEK293 cells, co-expression of HCN1 with TRIP8b resulted in translocation of the channels from the cell surface to large intracellular puncta where both TRIP8b and clathrin were concentrated. These puncta co-localized partially with an early endosome marker and strongly overlapped with lysosome staining reagent. When HCN1 was co-expressed with a clathrin-non-binding mutant of TRIP8b, clathrin did not translocate to HCN1 and TRIP8b-containing puncta, suggesting that TRIP8b interacts with HCN and clathrin independently. We found TRIP8b present in the fraction of clathrin-coated vesicles purified from brain tissues. Stripping the clathrin coat proteins from the vesicles with Tris alkaline buffer resulted in concomitant release of TRIP8b. Our data suggest complex regulatory functions of TRIP8b in neuronal endocytosis through independent interaction with membrane proteins and components of the clathrin coat.

  13. Deyev I.E., Sohet F., Vassilenko K.P., Serova O.V., Popova N.V., Zozulya S.A., Burova E.B., Houillier P., Rzhevsky D.I., Berchatova A.A., Murashev A.N., Chugunov A.O., Efremov R.G., Nikolsky N.N., Bertelli E., Eladari D., Petrenko A.G. (2011). Insulin receptor-related receptor as an extracellular alkali sensor. Cell Metab. 13 (6), 679–89 [+]

    The insulin receptor-related receptor (IRR), an orphan receptor tyrosine kinase of the insulin receptor family, can be activated by alkaline media both in vitro and in vivo at pH >7.9. The alkali-sensing property of IRR is conserved in frog, mouse, and human. IRR activation is specific, dose-dependent and quickly reversible and demonstrates positive cooperativity. It also triggers receptor conformational changes and elicits intracellular signaling. The pH sensitivity of IRR is primarily defined by its L1F extracellular domains. IRR is predominantly expressed in organs that come in contact with mildly alkaline media. In particular, IRR is expressed in the cell subsets of the kidney that secrete bicarbonate into urine. Disruption of IRR in mice impairs the renal response to alkali loading attested by development of metabolic alkalosis and decreased urinary bicarbonate excretion in response to this challenge. We therefore postulate that IRR is an alkali sensor that functions in the kidney to manage metabolic bicarbonate excess.

  14. Serova O.V., Popova N.V., Petrenko A.G., Deyev I.E. (2010). Association of the subunits of the calcium-independent receptor of α-latrotoxin. Biochem. Biophys. Res. Commun. 402 (4), 658–62 [+]

    CIRL-1 also called latrophilin 1 or CL belongs to the family of adhesion G protein-coupled receptors (GPCRs). As all members of adhesion GPCR family CIRL-1 consists of two heterologous subunits, extracellular hydrophilic p120 and heptahelical membrane protein p85. Both CIRL-1 subunits are encoded by one gene but as a result of intracellular proteolysis of precursor, mature receptor has two-subunit structure. It was also shown that a minor portion of the CIRL-1 receptor complexes dissociates, producing the soluble receptor ectodomain, and this dissociation is due to the second cleavage at the site between the site of primary proteolysis and the first transmembrane domain. Recently model of independent localization p120 and p85 on the cell surface was proposed. In this article we evaluated the amount of p120-p85 complex still presented on the cellular membrane and confirmed that on cell surface major amount of mature CIRL-1 presented as a p120-p85 subunit complex.

  15. Deyev I.E., Petrenko A.G. (2010). Regulation of CIRL-1 proteolysis and trafficking. Biochimie 92 (4), 418–22 [+]

    Calcium-independent receptor of alpha-latrotoxin (CIRL-1) is an adhesion G protein-coupled receptor implicated in the regulation of exocytosis. CIRL-1 biosynthesis involves constitutive proteolytic processing that takes place in the endoplasmic reticulum, requires the receptor's GPS domain, and yields heterologous two-subunit receptor complexes. It was proposed that the GPS-directed cleavage is based on cis-autoproteolysis. In this study, we demonstrate that activators of protein kinase C - PMA and ionomycin, can inhibit the cleavage of CIRL-1 precursor in transfected cells. Both reagents also downregulate trafficking of CIRL-1 to the cell surface that results in accumulation of the uncleaved receptor precursor inside the cells. Experiments with a non-cleavable soluble mutant of CIRL-1 showed that the downregulation of the receptor trafficking is independent of its cleavage. Our data suggest that the GPS proteolysis of CIRL-1 is not a purely autocatalytic process and may involve auxiliary proteins or factors that become available in the course of CIRL-1 trafficking.

  16. Krasnoperov V., Deyev I.E., Serova O.V., Xu C., Lu Y., Buryanovsky L., Gabibov A.G., Neubert T.A., Petrenko A.G. (2009). Dissociation of the subunits of the calcium-independent receptor of alpha-latrotoxin as a result of two-step proteolysis. Biochemistry 48 (14), 3230–8 [+]

    CIRL (the calcium-independent receptor of alpha-latrotoxin), a neuronal cell surface receptor implicated in the regulation of exocytosis, is a member of the GPS family of chimeric cell adhesion/G protein-coupled receptors. The predominant form of CIRL is a membrane-bound complex of two subunits, p120 and p85. Extracellularly oriented p120 contains hydrophilic cell adhesion domains, whereas p85 is a heptahelical membrane protein. Both subunits are encoded by the same gene and represent products of intracellular proteolytic processing of the CIRL precursor. In this study, we demonstrate that a soluble form of CIRL also exists in vitro and in vivo. It results from the further cleavage of CIRL by a second protease. The site of the second cleavage is located in the short N-terminal extracellular tail of p85, between the GPS domain and the first transmembrane segment of CIRL. Thus, the soluble form of CIRL represents a complex of p120 noncovalently bound to a 15 amino acid residue N-terminal peptide fragment of p85. We have previously shown that mutations of CIRL in the GPS domain inhibit intracellular proteolytic processing and also result in the absence of the receptors from the cell surface. Our current data suggest that although CIRL trafficking to the cell membrane is impaired by mutations in the GPS region, it is not blocked completely. However, at the cell surface, the noncleaved mutants are preferentially targeted by the second protease that sheds the extracellular subunit. Therefore, the two-step proteolytic processing may represent a regulatory mechanism that controls cell surface expression of membrane-bound and soluble forms of CIRL.

  17. Serova O.V., Deyev I.E., Petrenko A.G. (2009). Novel GPS-containing G protein-coupled receptor from Monosiga brevicollis. Dokl. Biochem. Biophys. 427, 191–4 ID:432
  18. Serova O.V., Popova N.V., Deev I.E., Petrenko A.G. (2009). Identification of proteins in complexes with alpha-latrotoxin receptors. Bioorg. Khim. 34 (6), 747–53 [+]

    A thorough analysis of proteins capable of interacting with presynaptic receptors of alpha-latrotoxin was carried out. The protein components of receptor complexes were isolated from rat brain membranes by affinity chromatography on immobilized alpha-latrotoxin and antibodies to the cytoplasmic moiety of the calcium-independent receptor of alpha-latrotoxin (CIRL) followed by analysis by mass spectrometry. Several proteins were identified, with structural proteins, intracellular signal proteins, and proteins involved in the endocytosis and transport of synaptic vesicles being among them.

  19. Popova N.V., Plotnikov A., Deev I.E., Petrenko A.G. (2009). Interaction of calcium-independent latrotoxin receptor with intracellular adapter protein TRIP8b. Dokl. Biochem. Biophys. 414, 149–51 [+]

    Кальций-независимый рецептор латротоксина (CIRL, calcium-independent receptor of α-latrotoxin или latrophilin) принадлежит недавно открытому семейству G-белок сопряженных рецепторов (GPCR), имеющих протяженную N-концевую внеклеточную область, включающую структурные домены белков клеточной адгезии. Данные семистолбовые рецепторы представляют интерес, поскольку способны сочетать внеклеточные адгезионные взаимодействия с внутриклеточными сигналами, опосредованными G-белками. В настоящее время для рецепторов CIRL неизвестны эндогенные лиганды, а также конкретные пути внутриклеточной передачи сигналов. Для выяснения молекулярных механизмов функционирования данных рецепторов мы провели поиск их внутриклеточных партнеров с помощью дрожжевой двухгибридной системы. Нами впервые, в качестве партнера CIRL, идентифицирован адаптерный белок TRIP8b. Полученные результаты позволяют предположить, что данный белок осуществляет роль регулятора транспорта CIRL с цитоплазматической мембраны в эндосомы.

  20. Popova N.V., Deyev I.E., Petrenko A.G. (2009). Analysis of structural determinants of alkali sensor IRR positive cooperativity. Dokl. Biochem. Biophys. 450, 160–3 ID:877
  21. Deyev I.E., Popova N.V., Petrenko A.G. (2009). Determination of Alkali-Sensing Parts of the Insulin Receptor-Related Receptor Using the Bioinformatic Approach. Acta Naturae 7 (2), 80–6 [+]

    IRR (insulin receptor-related receptor) is a receptor tyrosine kinase belonging to the insulin receptor family, which also includes insulin receptor and IGF-IR receptor. We have previously shown that IRR is activated by extracellular fluid with pH > 7.9 and regulates excess alkali excretion in the body. We performed a bioinformatic analysis of the pH-sensitive potential of all three members of the insulin receptor family of various animal species (from frog to man) and their chimeras with swapping of different domains in the extracellular region. An analysis using the AcalPred program showed that insulin receptor family proteins are divided into two classes: one class with the optimal working pH in the acidic medium (virtually all insulin receptor and insulin-like growth factor receptor orthologs, except for the IGF-IR ortholog from Xenopus laevis) and the second class with the optimal working pH in the alkaline medium (all IRR orthologs). The program had predicted that the most noticeable effect on the pH-sensitive property of IRR would be caused by the replacement of the L1 and C domains in its extracellular region, as well as the replacement of the second and third fibronectin repeats. It had also been assumed that replacement of the L2 domain would have the least significant effect on the alkaline sensitivity of IRR. To test the in silico predictions, we obtained three constructs with swapping of the L1C domains, the third L2 domain, and all three domains L1CL2 of IRR with similar domains of the insulin-like growth factor receptor. We found that replacement of the L1C and L1CL2 domains reduces the receptor's ability to be activated with alkaline pH, thus increasing the half-maximal effective concentration by about 100%. Replacement of the L2 domain increased the half-maximal effective concentration by 40%. Thus, our results indicate the high predictive potential of the AcalPred algorithm, not only for the pH-sensitive enzymes, but also for pH-sensitive receptors.

  22. Deev I.E., Vasilenko K.P., Kurmangaliev E.Z.h., Serova O.V., Popova N.V., Galagan Y.S., Burova E.B., Zozulya S.A., Nikolskii N.N., Petrenko A.G. (2009). Effect of changes in ambient pH on phosphorylation of cellular proteins. Dokl. Biochem. Biophys. 408, 184–7 ID:1298
  23. Popova N.V., Plotnikov A.N., Ziganshin R.K.h., Deyev I.E., Petrenko A.G. (2008). Analysis of proteins interacting with TRIP8b adapter. Biochemistry Mosc. 73 (6), 644–51 [+]

    Calcium-independent receptor of latrotoxin (CIRL) is an orphan heptahelical receptor implicated in regulation of exocytosis. To characterize molecular mechanisms of CIRL functioning, we searched for its intracellular partners using the yeast two-hybrid SR system with the cytoplasmic C-terminal fragment of CIRL as bait. One of the interacting proteins was identified as TRIP8b, a putative cytosolic adapter protein with multiple tetratricopeptide repeats. To understand functional significance of CIRL-TRIP8b interaction, we further isolated TRIP8b-interacting proteins by affinity chromatography of brain extracts on immobilized recombinant TRIP8b. Sixteen proteins were identified by mass spectrometry in the purified preparations. Clathrin and subunits of AP2 complex appeared to be the major TRIP8b-interacting proteins. Our data suggest a role of TRIP8b in receptor-mediated endocytosis.