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Liontos LM, Dissanayake D, Ohashi PS, Weiss A, Dragone LL, McGlade CJ. The Src-Like Adaptor Protein Regulates GM-CSFR Signaling and Monocytic Dendritic Cell Maturation. THE JOURNAL OF IMMUNOLOGY 2011; 186:1923-33. [DOI: 10.4049/jimmunol.0903292] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Gasparrini F, Molfetta R, Santoni A, Paolini R. Cbl Family Proteins: Balancing FcεRI-Mediated Mast Cell and Basophil Activation. Int Arch Allergy Immunol 2011; 156:16-26. [DOI: 10.1159/000322236] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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53
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Ye S, Cihil K, Stolz DB, Pilewski JM, Stanton BA, Swiatecka-Urban A. c-Cbl facilitates endocytosis and lysosomal degradation of cystic fibrosis transmembrane conductance regulator in human airway epithelial cells. J Biol Chem 2010; 285:27008-27018. [PMID: 20525683 DOI: 10.1074/jbc.m110.139881] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated Cl(-) channel expressed in the apical membrane of fluid-transporting epithelia. The apical membrane density of CFTR channels is determined, in part, by endocytosis and the postendocytic sorting of CFTR for lysosomal degradation or recycling to the plasma membrane. Although previous studies suggested that ubiquitination plays a role in the postendocytic sorting of CFTR, the specific ubiquitin ligases are unknown. c-Cbl is a multifunctional molecule with ubiquitin ligase activity and a protein adaptor function. c-Cbl co-immunoprecipitated with CFTR in primary differentiated human bronchial epithelial cells and in cultured human airway cells. Small interfering RNA-mediated silencing of c-Cbl increased CFTR expression in the plasma membrane by inhibiting CFTR endocytosis and increased CFTR-mediated Cl(-) currents. Silencing c-Cbl did not change the expression of the ubiquitinated fraction of plasma membrane CFTR. Moreover, the c-Cbl mutant with impaired ubiquitin ligase activity (FLAG-70Z-Cbl) did not affect the plasma membrane expression or the endocytosis of CFTR. In contrast, the c-Cbl mutant with the truncated C-terminal region (FLAG-Cbl-480), responsible for protein adaptor function, had a dominant interfering effect on the endocytosis and plasma membrane expression of CFTR. Moreover, CFTR and c-Cbl co-localized and co-immunoprecipitated in early endosomes, and silencing c-Cbl reduced the amount of ubiquitinated CFTR in early endosomes. In summary, our data demonstrate that in human airway epithelial cells, c-Cbl regulates CFTR by two mechanisms: first by acting as an adaptor protein and facilitating CFTR endocytosis by a ubiquitin-independent mechanism, and second by ubiquitinating CFTR in early endosomes and thereby facilitating the lysosomal degradation of CFTR.
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Affiliation(s)
- Siying Ye
- Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire 03755
| | - Kristine Cihil
- Department of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15224
| | - Donna Beer Stolz
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15201
| | - Joseph M Pilewski
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15201; Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 152224
| | - Bruce A Stanton
- Department of Physiology, Dartmouth Medical School, Hanover, New Hampshire 03755
| | - Agnieszka Swiatecka-Urban
- Department of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania 15224; Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15201.
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Ryan PE, Sivadasan-Nair N, Nau MM, Nicholas S, Lipkowitz S. The N terminus of Cbl-c regulates ubiquitin ligase activity by modulating affinity for the ubiquitin-conjugating enzyme. J Biol Chem 2010; 285:23687-98. [PMID: 20525694 DOI: 10.1074/jbc.m109.091157] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cbl proteins are ubiquitin ligases (E3s) that play a significant role in regulating tyrosine kinase signaling. There are three mammalian family members: Cbl, Cbl-b, and Cbl-c. All have a highly conserved N-terminal tyrosine kinase binding domain, a catalytic RING finger domain, and a C-terminal proline-rich domain that mediates interactions with Src homology 3 (SH3) containing proteins. Although both Cbl and Cbl-b have been studied widely, little is known about Cbl-c. Published reports have demonstrated that the N terminus of Cbl and Cbl-b have an inhibitory effect on their respective E3 activity. However, the mechanism for this inhibition is still unknown. In this study we demonstrate that the N terminus of Cbl-c, like that of Cbl and Cbl-b, inhibits the E3 activity of Cbl-c. Furthermore, we map the region responsible for the inhibition to the EF-hand and SH2 domains. Phosphorylation of a critical tyrosine (Tyr-341) in the linker region of Cbl-c by Src or a phosphomimetic mutation of this tyrosine (Y341E) is sufficient to increase the E3 activity of Cbl-c. We also demonstrate for the first time that phosphorylation of Tyr-341 or the Y341E mutation leads to a decrease in affinity for the ubiquitin-conjugating enzyme (E2), UbcH5b. The decreased affinity of the Y341E mutant Cbl-c for UbcH5b results in a more rapid turnover of bound UbcH5b coincident with the increased E3 activity. These data suggest that the N terminus of Cbl-c contributes to the binding to the E2 and that phosphorylation of Tyr-341 leads to a decrease in affinity and an increase in the E3 activity of Cbl-c.
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Affiliation(s)
- Philip E Ryan
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, MD 20892, USA
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Kales SC, Ryan PE, Nau MM, Lipkowitz S. Cbl and human myeloid neoplasms: the Cbl oncogene comes of age. Cancer Res 2010; 70:4789-94. [PMID: 20501843 DOI: 10.1158/0008-5472.can-10-0610] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cbl was originally discovered in 1989 as the cellular homolog of the v-Cbl oncogene, the transforming gene of the Cas NS-1 murine retrovirus that causes myeloid leukemia and lymphomas in mice. Cbl is a member of a family of RING finger ubiquitin ligases that negatively regulate signaling by tyrosine kinases and that function as adaptor proteins to regulate signaling positively. Until the past 2 years, there was little evidence that Cbl proteins were involved in human malignancies. Recent publications have shown homozygous mutations in Cbl in human myeloid neoplasms. Although in vitro and animal transformation models suggested that mutant forms of Cbl acted as an oncogene, the cellular role suggested that the protein could serve as a tumor suppressor gene. The recent data begin to reconcile this paradox as the loss of ubiquitin ligase function (the tumor suppressor function) is coupled to the maintenance of the positive signaling function (the oncogene function). These data also provide insight into potential therapeutic approaches to myeloid disorders harboring Cbl mutations.
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Affiliation(s)
- Stephen C Kales
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4256, USA
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c-Cbl deficiency leads to diminished lymphocyte development and functions in an age-dependent manner. Proc Natl Acad Sci U S A 2010; 107:8316-21. [PMID: 20404156 DOI: 10.1073/pnas.0914496107] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Aging is broadly defined as a progressive decline of tissue and organ functions due to deregulation of various cell intrinsic and extrinsic factors. In the immune system, aging preferentially affects lymphopoiesis and thus results in the reduced competence of the adaptive immune system in the elderly. Despite recent discoveries that shed light on the molecular basis of aging, pathways that lead to diminished lymphoid development in aging individuals remain largely unknown. In the present study, we document that a deficiency of the E3 ubiquitin ligase c-Cbl in lymphocytes results in an age-dependent lymphopenia. c-Cbl-deficient mice show normal frequencies of lymphocytes at 12 weeks of age; however, their development and functions were remarkably diminished at 24 weeks after birth. Intriguingly, c-Cbl mutant lymphocytes displayed increased responses to IL7 in vitro and failed to down-regulate surface levels of IL7Ralpha. Further, our biochemical studies have identified an interaction of c-Cbl with IL7Ralpha and have unraveled the involvement of c-Cbl in the ubiquitylation of IL7Ralpha. In essence, our studies demonstrate that a lack of signaling events mediated by c-Cbl might result in diminished lymphocyte development and functions, particularly, at the later stages of life.
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Ishido S, Matsuki Y, Goto E, Kajikawa M, Ohmura-Hoshino M. MARCH-I: a new regulator of dendritic cell function. Mol Cells 2010; 29:229-32. [PMID: 20213309 DOI: 10.1007/s10059-010-0051-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Accepted: 01/20/2010] [Indexed: 01/09/2023] Open
Abstract
We and other groups have demonstrated that the expression level of MHC class II (MHC II) is regulated through ubiquitination of the MHC II beta chain. We also reported that MARCH-I, an E3 ubiquitin ligase, is critical for this process. At present, however, the importance of MARCH-I-mediated MHC II regulation in vivo is still unknown. In this review, we will summarize recent advances in our understanding of MARCH-I-mediated MHC II ubiquitination, and discuss how we can overcome the difficulties inherent in these studies.
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Affiliation(s)
- Satoshi Ishido
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, 230-0045, Japan.
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58
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Gain-of-function of mutated C-CBL tumour suppressor in myeloid neoplasms. Nature 2009; 460:904-8. [PMID: 19620960 DOI: 10.1038/nature08240] [Citation(s) in RCA: 337] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Accepted: 06/30/2009] [Indexed: 01/06/2023]
Abstract
Acquired uniparental disomy (aUPD) is a common feature of cancer genomes, leading to loss of heterozygosity. aUPD is associated not only with loss-of-function mutations of tumour suppressor genes, but also with gain-of-function mutations of proto-oncogenes. Here we show unique gain-of-function mutations of the C-CBL (also known as CBL) tumour suppressor that are tightly associated with aUPD of the 11q arm in myeloid neoplasms showing myeloproliferative features. The C-CBL proto-oncogene, a cellular homologue of v-Cbl, encodes an E3 ubiquitin ligase and negatively regulates signal transduction of tyrosine kinases. Homozygous C-CBL mutations were found in most 11q-aUPD-positive myeloid malignancies. Although the C-CBL mutations were oncogenic in NIH3T3 cells, c-Cbl was shown to functionally and genetically act as a tumour suppressor. C-CBL mutants did not have E3 ubiquitin ligase activity, but inhibited that of wild-type C-CBL and CBL-B (also known as CBLB), leading to prolonged activation of tyrosine kinases after cytokine stimulation. c-Cbl(-/-) haematopoietic stem/progenitor cells (HSPCs) showed enhanced sensitivity to a variety of cytokines compared to c-Cbl(+/+) HSPCs, and transduction of C-CBL mutants into c-Cbl(-/-) HSPCs further augmented their sensitivities to a broader spectrum of cytokines, including stem-cell factor (SCF, also known as KITLG), thrombopoietin (TPO, also known as THPO), IL3 and FLT3 ligand (FLT3LG), indicating the presence of a gain-of-function that could not be attributed to a simple loss-of-function. The gain-of-function effects of C-CBL mutants on cytokine sensitivity of HSPCs largely disappeared in a c-Cbl(+/+) background or by co-transduction of wild-type C-CBL, which suggests the pathogenic importance of loss of wild-type C-CBL alleles found in most cases of C-CBL-mutated myeloid neoplasms. Our findings provide a new insight into a role of gain-of-function mutations of a tumour suppressor associated with aUPD in the pathogenesis of some myeloid cancer subsets.
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Wu H, Wu H, Li H, Wu H, Li H, Guo J. Spry2-mediated inhibition of the Ras/ERK pathway through interaction with Src kinase following cerebral ischemia. Brain Inj 2009; 22:275-81. [DOI: 10.1080/02699050801911295] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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60
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Calcium regulation of mitochondria motility and morphology. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:1363-73. [PMID: 19138660 DOI: 10.1016/j.bbabio.2008.12.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 12/10/2008] [Accepted: 12/10/2008] [Indexed: 12/21/2022]
Abstract
In the Fifties, electron microscopy studies on neuronal cells showed that mitochondria typically cluster at synaptic terminals, thereby introducing the concept that proper mitochondria trafficking and partitioning inside the cell could provide functional support to the execution of key physiological processes. Today, the notion that a central event in the life of every eukaryotic cell is to configure, maintain, and reorganize the mitochondrial network at sites of high energy demand in response to environmental and cellular cues is well established, and the challenge ahead is to define the underlying molecular mechanisms and regulatory pathways. Recent pioneering studies have further contributed to place mitochondria at the center of the cell biology by showing that the machinery governing remodeling of mitochondria shape and structure regulates the functional output of the organelle as the powerhouse of the cell, the gateway to programmed cell death, and the platform for Ca(2+) signaling. Thus, a raising issue is to identify the cues integrating mitochondria trafficking and dynamics into cell physiology and metabolism. Given the versatile function of calcium as a second messenger and of the role of mitochondria as a major calcium store, evidences are emerging linking Ca(2+) transients to the modulation of mitochondrial activities. This review focuses on calcium as a switch controlling mitochondria motility and morphology in steady state, stressed, and pathological conditions.
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61
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Abstract
Clathrin-mediated endocytosis sorts for degradation of more than 50 different growth factor receptors capable of relaying growth and differentiation signals by means of their cytoplasm-facing, intrinsic tyrosine kinase activity. The kinetics and alternative routings of receptor endocytosis critically regulate growth factor signaling, which underscores the importance of understanding mechanisms underlying fail-safe operation (robustness) and fidelity of the pathway. Like other robust systems, a layered hub-centric network controls receptor endocytosis. Characteristically, the modular hubs (e.g., AP2-Eps15 and Hrs) contain a membrane-anchoring lipid-binding domain, an ubiquitin-binding module, which recruits ubiquitinylated cargo, and a machinery enabling homo-assembly. Scheduled hub transitions, as well as cascades of Rab family guanosine triphosphatases and membrane bending machineries, define points of commitment to vesicle budding, thereby securing unidirectional trafficking. System's bistability permits stimulation by a growth factor, which oscillates a series of switches based on posttranslational protein modifications (i.e., phosphorylation, ubiquitinylation and neddylation), as well as transient low-affinity/high-avidity protein assemblies. Cbl family ubiquitin ligases, along with a set of phosphotyrosine-binding adaptors (e.g., Grb2), integrate receptor endocytosis into the densely wired networks of signal transduction pathways, which are involved in health and disease.
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Affiliation(s)
- Yaara Zwang
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, Israel
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62
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Crinelli R, Bianchi M, Menotta M, Carloni E, Giacomini E, Pennati M, Magnani M. Ubiquitin over-expression promotes E6AP autodegradation and reactivation of the p53/MDM2 pathway in HeLa cells. Mol Cell Biochem 2008; 318:129-45. [DOI: 10.1007/s11010-008-9864-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
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63
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Rathinam C, Thien CBF, Langdon WY, Gu H, Flavell RA. The E3 ubiquitin ligase c-Cbl restricts development and functions of hematopoietic stem cells. Genes Dev 2008; 22:992-7. [PMID: 18413713 DOI: 10.1101/gad.1651408] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hematopoietic stem cells (HSCs) are multipotent progenitors that give rise to all types of blood cells. In the present study, we document that HSC development and functions are negatively regulated by the E3 ubiquitin ligase c-Cbl (casitas B-cell lymphoma). HSCs of c-Cbl(-/-) mice exhibit augmented pool size, hyperproliferation, greater competence, and enhanced long-term repopulating capacity. Our mechanistic studies identified that c-Cbl(-/-) HSCs are hyperresponsive to thrombopoietin (TPO) and display elevated levels of STAT5 phosphorylation, thus leading to increased c-Myc expression. In essence, our data unequivocally identify c-Cbl as a novel negative regulator of developmental and functional properties of HSCs.
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Affiliation(s)
- Chozhavendan Rathinam
- Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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64
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Isakov N. A new twist to adaptor proteins contributes to regulation of lymphocyte cell signaling. Trends Immunol 2008; 29:388-96. [PMID: 18599349 DOI: 10.1016/j.it.2008.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Revised: 04/10/2008] [Accepted: 04/23/2008] [Indexed: 01/23/2023]
Abstract
Cell growth and differentiation are highly controlled processes mediated by effector molecules, which are regulated by posttranslational chemical modifications. Adaptor molecules are critical players in these mechanisms because of their ability to simultaneously interact with multiple effector molecules and orchestrate the assembly of signaling complexes downstream of activated surface receptors. One family of adaptor molecules includes the CrkII/CrkL proteins that are also involved in the regulation of lymphocyte function. Although Crk proteins are amenable to regulation by protein tyrosine kinases, recent data suggest that peptidyl-prolyl cis-trans isomerases (PPIases) can alter their conformation and hence their ability to associate with binding partners. This emerging new function of PPIases is the subject of the current review.
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Affiliation(s)
- Noah Isakov
- The Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences and the Cancer Research Center, Ben Gurion University of the Negev, Beer Sheva 84105, Israel.
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65
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Tanaka N, Kyuuma M, Sugamura K. Endosomal sorting complex required for transport proteins in cancer pathogenesis, vesicular transport, and non-endosomal functions. Cancer Sci 2008; 99:1293-303. [PMID: 18429951 PMCID: PMC11158640 DOI: 10.1111/j.1349-7006.2008.00825.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Revised: 02/27/2008] [Accepted: 02/29/2008] [Indexed: 12/18/2022] Open
Abstract
Endosomal sorting complex required for transport (ESCRT) proteins form a multicomplex sorting machinery that controls multivesicular body (MVB) formation and the sorting of ubiquitinated membrane proteins to the endosomes. Being sorted to the MVB generally results in the lysosome-dependent degradation of cell-surface receptors, and defects in this machinery induce dysregulated receptor traffic and turnover. Recent lessons from gene targeting and silencing methodologies have implicated the ESCRT in normal development, cell differentiation, and growth, as well as in the budding of certain enveloped viruses. Furthermore, it is becoming apparent that the dysregulation of ESCRT proteins is involved in the development of various human diseases, including many types of cancers and neurodegenerative disorders. Here, we summarize the roles of ESCRT proteins in MVB sorting processes and the regulation of tumor cells, and we discuss some of their other functions that are unrelated to vesicular transport.
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Affiliation(s)
- Nobuyuki Tanaka
- Department of Microbiology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
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66
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Lee H, Gaughan JP, Tsygankov AY. c-Cbl facilitates cytoskeletal effects in v-Abl transformed fibroblast through Rac1- and Rap1-mediated signaling. Int J Biochem Cell Biol 2008; 40:1930-43. [PMID: 18403249 DOI: 10.1016/j.biocel.2008.02.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 01/24/2008] [Accepted: 02/10/2008] [Indexed: 11/24/2022]
Abstract
c-Cbl functions as a multifunctional adaptor and an E3 ubiquitin ligase. Several studies have shown that c-Cbl is involved in cytoskeleton-mediated events, but the molecular mechanisms linking c-Cbl to cytoskeletal rearrangements remain to be elucidated. Our previous results indicated that c-Cbl facilitates spreading and migration of v-Abl-transformed NIH 3T3 fibroblasts and suggested that small GTPases play important roles in the cytoskeletal effects of c-Cbl in this system. To elucidate the individual contributions of small GTPases to these effects, we assessed the roles of endogenous Rac1, RhoA and Rap1 in the c-Cbl-dependent spreading and migration of v-Abl-transformed fibroblasts overexpressing c-Cbl, using RNAi. Furthermore, since it has been shown that Rap1 can act as an upstream regulator of Rac1 in inducing cell spreading, we analyzed the interplay between Rap1 and Rac1 in the signaling pathways connecting c-Cbl to the cytoskeletal events. Our results indicate that Rac1 is essential for cell migration and spreading, whereas activation of RhoA exerts a negative effect. We have also shown that Rap1 is essential for cell spreading, although not for migration in our experimental system. Furthermore, we provide evidence that Rap1 is located upstream of Rac1 in one of the signaling pathways that regulate c-Cbl-facilitated cell spreading. Overall, our findings are consistent with the model describing the connection of c-Cbl to the cytoskeletal rearrangements via two pathways, one of which is mediated by PI3K and Rac1, and the other, by CrkL/C3G, Rap1 and Rac1.
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Affiliation(s)
- Hojin Lee
- Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA, USA
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67
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Diverse cellular functions of the Hsp90 molecular chaperone uncovered using systems approaches. Cell 2008; 131:121-35. [PMID: 17923092 DOI: 10.1016/j.cell.2007.07.036] [Citation(s) in RCA: 369] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 05/18/2007] [Accepted: 07/20/2007] [Indexed: 01/31/2023]
Abstract
A comprehensive understanding of the cellular functions of the Hsp90 molecular chaperone has remained elusive. Although Hsp90 is essential, highly abundant under normal conditions, and further induced by environmental stress, only a limited number of Hsp90 "clients" have been identified. To define Hsp90 function, a panel of genome-wide chemical-genetic screens in Saccharomyces cerevisiae were combined with bioinformatic analyses. This approach identified several unanticipated functions of Hsp90 under normal conditions and in response to stress. Under normal growth conditions, Hsp90 plays a major role in various aspects of the secretory pathway and cellular transport; during environmental stress, Hsp90 is required for the cell cycle, meiosis, and cytokinesis. Importantly, biochemical and cell biological analyses validated several of these Hsp90-dependent functions, highlighting the potential of our integrated global approach to uncover chaperone functions in the cell.
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68
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Goto E, Mito-Yoshida M, Uematsu M, Aoki M, Matsuki Y, Ohmura-Hoshino M, Hotta H, Miyagishi M, Ishido S. An excellent monitoring system for surface ubiquitination-induced internalization in mammals. PLoS One 2008; 3:e1490. [PMID: 18231577 PMCID: PMC2204058 DOI: 10.1371/journal.pone.0001490] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2007] [Accepted: 12/30/2007] [Indexed: 11/23/2022] Open
Abstract
Background At present, it is difficult to visualize the internalization of surface receptors induced by ubiquitination that is taken place at the plasma membrane in mammals. This problem makes it difficult to reveal molecular basis for ubiquitination-mediated internalization in mammals. Methodology/Principle Findings In order to overcome it, we have generated T-REx-c-MIR, a novel mammalian Tet-on B cell line using a constitutively active E3 ubiquitin ligase, c-MIR, and its artificial target molecule. By applying the surface biotinylation method to T-REx-c-MIR, we succeeded to monitor the fate of surface target molecules after initiation of ubiquitination process by doxycycline (Dox)-induced c-MIR expression. Target molecules that pre-existed at the plasma membrane before induction of c-MIR expression were oligo-ubiquitinated and degraded by Dox-induced c-MIR expression. Dox-induced c-MIR expression initiated rapid internalization of surface target molecules, and blockage of the internalization induced the accumulation of the surface target molecules that were newly ubiquitinated by c-MIR. Inhibition of the surface ubiquitination by down-regulating ubiquitin conjugating enzyme E2 impaired the internalization of target molecules. Finally, a complex of c-MIR and target molecule was detected at the plasma membrane. Conclusions/Significances These results demonstrate that in T-REx-c-MIR, surface target molecule is ubiquitinated at the plasma membrane and followed by being internalized from the plasma membrane. Thus, T-REx-c-MIR is a useful experimental tool to analyze how surface ubiquitination regulates internalization in mammals.
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Affiliation(s)
- Eiji Goto
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Mari Mito-Yoshida
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Mika Uematsu
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Masami Aoki
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Yohei Matsuki
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Mari Ohmura-Hoshino
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
| | - Hak Hotta
- Department of Pathology and Microbiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Makoto Miyagishi
- 21st Century COE Program, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Satoshi Ishido
- Laboratory for Infectious Immunity, RIKEN Research Center for Allergy and Immunology, Yokohama, Kanagawa, Japan
- * To whom correspondence should be addressed. E-mail:
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70
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Peruzzi G, Molfetta R, Gasparrini F, Vian L, Morrone S, Piccoli M, Frati L, Santoni A, Paolini R. The adaptor molecule CIN85 regulates Syk tyrosine kinase level by activating the ubiquitin-proteasome degradation pathway. THE JOURNAL OF IMMUNOLOGY 2007; 179:2089-96. [PMID: 17675467 DOI: 10.4049/jimmunol.179.4.2089] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Triggering of mast cells and basophils by IgE and Ag initiates a cascade of biochemical events that lead to cell degranulation and the release of allergic mediators. Receptor aggregation also induces a series of biochemical events capable of limiting FcepsilonRI-triggered signals and functional responses. Relevant to this, we have recently demonstrated that Cbl-interacting 85-kDa protein (CIN85), a multiadaptor protein mainly involved in the process of endocytosis and vesicle trafficking, regulates the Ag-dependent endocytosis of the IgE receptor, with consequent impairment of FcepsilonRI-mediated cell degranulation. The purpose of this study was to further investigate whether CIN85 could alter the FcepsilonRI-mediated signaling by affecting the activity and/or expression of molecules directly implicated in signal propagation. We found that CIN85 overexpression inhibits the FcepsilonRI-induced tyrosine phosphorylation of phospholipase Cgamma, thus altering calcium mobilization. This functional defect is associated with a substantial decrease of Syk protein levels, which are restored by the use of selective proteasome inhibitors, and it is mainly due to the action of the ubiquitin ligase c-Cbl. Furthermore, coimmunoprecipitation experiments demonstrate that CIN85 overexpression limits the ability of Cbl to bind suppressor of TCR signaling 1 (Sts1), a negative regulator of Cbl functions, while CIN85 knockdown favors the formation of Cbl/Sts1 complexes. Altogether, our findings support a new role for CIN85 in regulating Syk protein levels in RBL-2H3 cells through the activation of the ubiquitin-proteasome pathway and provide a mechanism for this regulation involving c-Cbl ligase activity.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/immunology
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antigens/immunology
- Antigens/metabolism
- Basophils/immunology
- Basophils/metabolism
- Calcium Signaling/genetics
- Calcium Signaling/immunology
- Cell Degranulation/genetics
- Cell Degranulation/immunology
- Cell Line
- Endocytosis/genetics
- Endocytosis/immunology
- Gene Expression
- Humans
- Immunoglobulin A/immunology
- Immunoglobulin A/metabolism
- Intracellular Signaling Peptides and Proteins/genetics
- Intracellular Signaling Peptides and Proteins/immunology
- Intracellular Signaling Peptides and Proteins/metabolism
- Mast Cells/immunology
- Mast Cells/metabolism
- Neoplasm Proteins/genetics
- Neoplasm Proteins/immunology
- Neoplasm Proteins/metabolism
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/immunology
- Nerve Tissue Proteins/metabolism
- Phospholipase C gamma
- Phosphorylation
- Proteasome Endopeptidase Complex/genetics
- Proteasome Endopeptidase Complex/immunology
- Proteasome Endopeptidase Complex/metabolism
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/immunology
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins c-cbl/genetics
- Proto-Oncogene Proteins c-cbl/immunology
- Proto-Oncogene Proteins c-cbl/metabolism
- Rats
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Receptors, IgE/genetics
- Receptors, IgE/immunology
- Receptors, IgE/metabolism
- Syk Kinase
- Ubiquitin/genetics
- Ubiquitin/immunology
- Ubiquitin/metabolism
- Ubiquitin-Protein Ligases/genetics
- Ubiquitin-Protein Ligases/immunology
- Ubiquitin-Protein Ligases/metabolism
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Affiliation(s)
- Giovanna Peruzzi
- Department of Experimental Medicine, Institute Pasteur-Fondazione Cenci Bolognetti, University La Sapienza, Rome, Italy
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71
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Peschard P, Kozlov G, Lin T, Mirza IA, Berghuis AM, Lipkowitz S, Park M, Gehring K. Structural basis for ubiquitin-mediated dimerization and activation of the ubiquitin protein ligase Cbl-b. Mol Cell 2007; 27:474-85. [PMID: 17679095 DOI: 10.1016/j.molcel.2007.06.023] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/02/2007] [Accepted: 06/20/2007] [Indexed: 11/18/2022]
Abstract
Cbl proteins are E3 ubiquitin ligases that are negative regulators of many receptor tyrosine kinases. Cbl-b and c-Cbl contain a ubiquitin-associated (UBA) domain, which is present in a variety of proteins involved in ubiquitin-mediated processes. Despite high sequence identity, Cbl UBA domains display remarkably different ubiquitin-binding properties. Here, we report the crystal structure of the UBA domain of Cbl-b in complex with ubiquitin at 1.9 A resolution. The structure reveals an atypical mechanism of ubiquitin recognition by the first helix of the UBA. Helices 2 and 3 of the UBA domain form a second binding surface, which mediates UBA dimerization in the crystal and in solution. Site-directed mutagenesis demonstrates that Cbl-b dimerization is regulated by ubiquitin binding and required for tyrosine phosphorylation of Cbl-b and ubiquitination of Cbl-b substrates. These studies demonstrate a role for ubiquitin in regulating biological activity by promoting protein dimerization.
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Affiliation(s)
- Pascal Peschard
- Department of Biochemistry, McGill University, Montréal, Canada
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72
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Rix U, Hantschel O, Dürnberger G, Remsing Rix LL, Planyavsky M, Fernbach NV, Kaupe I, Bennett KL, Valent P, Colinge J, Köcher T, Superti-Furga G. Chemical proteomic profiles of the BCR-ABL inhibitors imatinib, nilotinib, and dasatinib reveal novel kinase and nonkinase targets. Blood 2007; 110:4055-63. [PMID: 17720881 DOI: 10.1182/blood-2007-07-102061] [Citation(s) in RCA: 517] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The BCR-ABL tyrosine kinase inhibitor imatinib represents the current frontline therapy in chronic myeloid leukemia. Because many patients develop imatinib resistance, 2 second-generation drugs, nilotinib and dasatinib, displaying increased potency against BCR-ABL were developed. To predict potential side effects and novel medical uses, we generated comprehensive drug-protein interaction profiles by chemical proteomics for all 3 drugs. Our studies yielded 4 major findings: (1) The interaction profiles of the 3 drugs displayed strong differences and only a small overlap covering the ABL kinases. (2) Dasatinib bound in excess of 30 Tyr and Ser/Thr kinases, including major regulators of the immune system, suggesting that dasatinib might have a particular impact on immune function. (3) Despite the high specificity of nilotinib, the receptor tyrosine kinase DDR1 was identified and validated as an additional major target. (4) The oxidoreductase NQO2 was bound and inhibited by imatinib and nilotinib at physiologically relevant drug concentrations, representing the first nonkinase target of these drugs.
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MESH Headings
- Benzamides
- Dasatinib
- Discoidin Domain Receptor 1
- Dose-Response Relationship, Drug
- Drug Resistance, Neoplasm
- Drug Screening Assays, Antitumor
- Fusion Proteins, bcr-abl
- Humans
- Imatinib Mesylate
- K562 Cells
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/enzymology
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/metabolism
- Piperazines/chemistry
- Piperazines/pharmacology
- Piperazines/therapeutic use
- Protein Kinase Inhibitors/chemistry
- Protein Kinase Inhibitors/pharmacology
- Protein Kinase Inhibitors/therapeutic use
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/metabolism
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/metabolism
- Proteomics
- Pyrimidines/chemistry
- Pyrimidines/pharmacology
- Pyrimidines/therapeutic use
- Quinone Reductases/antagonists & inhibitors
- Quinone Reductases/metabolism
- Receptor Protein-Tyrosine Kinases/antagonists & inhibitors
- Receptor Protein-Tyrosine Kinases/metabolism
- Thiazoles/chemistry
- Thiazoles/pharmacology
- Thiazoles/therapeutic use
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Affiliation(s)
- Uwe Rix
- Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna
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73
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Magnifico A, Albano L, Campaner S, Campiglio M, Pilotti S, Ménard S, Tagliabue E. Protein kinase Calpha determines HER2 fate in breast carcinoma cells with HER2 protein overexpression without gene amplification. Cancer Res 2007; 67:5308-17. [PMID: 17545611 DOI: 10.1158/0008-5472.can-06-3936] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In some HER2-positive breast tumors, cell surface overexpression of HER2 is not associated with gene amplification but may instead rest in altered gene transcription, half-life, or recycling of the oncoprotein. Here, we show that HER2 overexpression in HER2 2+ carcinomas is associated with neither an increase in gene transcription nor a deregulation in the ubiquitin-dependent pathways, but instead seems to be regulated by protein kinase Calpha (PKCalpha) activity. The stimulation of PKCalpha up-regulated HER2 expression, whereas PKCalpha inhibition by pharmacologic treatments and PKCalpha-specific small interfering RNA led to a dramatic down-regulation of HER2 levels only in breast cancer cells HER2 2+. Consistent with the in vitro data, our biochemical analysis of HER2 2+ human primary breast specimens revealed significantly higher levels of phosphorylated PKCalpha compared with HER2-negative tumors. Inhibition of HER2 activation by the tyrosine kinase inhibitor lapatinib led to decreased levels of PKCalpha phosphorylation, clearly indicating a cross-talk between PKCalpha and HER2 molecules. These data suggest that HER2 overexpression in HER2 2+ carcinomas is due to an accumulation of the recycled oncoprotein to the cell surface induced by activated PKCalpha.
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Affiliation(s)
- Alessandra Magnifico
- Molecular Targeting Unit, Department of Experimental Oncology, National Cancer Institute, Foundation IRCCS, Milan, Italy
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74
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Sakane A, Hatakeyama S, Sasaki T. Involvement of Rabring7 in EGF receptor degradation as an E3 ligase. Biochem Biophys Res Commun 2007; 357:1058-64. [PMID: 17462600 DOI: 10.1016/j.bbrc.2007.04.052] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2007] [Accepted: 04/10/2007] [Indexed: 01/29/2023]
Abstract
Rab7, a member of the Rab family small G proteins, is involved in the late stage of the endocytic pathway. We previously identified a Rab7 target protein, Rabring7, which contains a RING finger domain at its C termini, but the precise role of Rabring7 remains unknown. In this study, we demonstrate using an in vitro ubiquitination assay with recombinant E1 and E2 proteins that Rabring7 has E3 ligase activity and that it preferentially reacts with Ubc4 and Ubc5 as its E2 proteins. Rabring7 ubiquitinated itself but not Rab7, and a mutation at Cys-229 in the RING finger domain (Rabring7C229S) completely diminished its E3 ligase activity. In the ligand-induced degradation of EGF receptor (EGFR), Rabring7 accelerated the degradation of EGFR, whereas Rabring7C229S inhibited the degradation induced by cCbl, another E3 ligase. These results suggest that Rabring7 is involved in the endocytic trafficking of EGFR through its E3 ligase activity.
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Affiliation(s)
- Ayuko Sakane
- Department of Biochemistry, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
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75
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Caligiuri MA, Briesewitz R, Yu J, Wang L, Wei M, Arnoczky KJ, Marburger TB, Wen J, Perrotti D, Bloomfield CD, Whitman SP. Novel c-CBL and CBL-b ubiquitin ligase mutations in human acute myeloid leukemia. Blood 2007; 110:1022-4. [PMID: 17475912 PMCID: PMC1924768 DOI: 10.1182/blood-2006-12-061176] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The CBL ubiquitin ligase targets a variety of activated tyrosine kinases (TKs) for degradation. Many TKs are mutationally or autocrine activated and/or often overexpressed at the mRNA and protein levels in acute leukemias. We hypothesized that CBL is mutated in patients with acute myeloid leukemia (AML). Four of 12 patients and the MOLM-13 cell line harbored c-CBL mutations, either RNA splicing mutations, missense mutations, or a nucleotide insertion. Additionally, 1 of the 12 patients harbored a missense mutation in the related CBL-b gene. Each c-CBL mutation involves the structurally important alpha-helix within the linker region, while the mutation in CBL-b was located in the Ub-E2 protein-binding RING finger. Short-interfering RNA knockdown of mutant c-CBL present in MOLM-13 cells was growth inhibitory. In summary, novel mutations in c-CBL and CBL-b have been identified in human AML and may represent potential targets for novel therapeutics.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Cell Line
- Cell Line, Tumor
- Female
- Humans
- Leukemia, Myeloid, Acute/enzymology
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/pathology
- Male
- Mutation, Missense
- Protein Structure, Secondary/genetics
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins c-cbl/genetics
- Proto-Oncogene Proteins c-cbl/metabolism
- RNA Splicing/genetics
- RNA, Small Interfering/genetics
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Affiliation(s)
- Michael A Caligiuri
- Integrated Biomeducal Graduate Program, Comprehensive Cancer Center, Ohio State University, Columbus, OH 23240, USA
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76
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Abstract
Tyrosyl phosphorylation plays a critical role in multiple signaling pathways regulating innate and acquired immunity. Although tyrosyl phosphorylation is a reversible process, we know much more about the functions of protein-tyrosine kinases (PTKs) than about protein-tyrosine phosphatases (PTPs). Genome sequencing efforts have revealed a large and diverse superfamily of PTPs, which can be subdivided into receptor-like (RPTPs) and nonreceptor (NRPTPs). The role of the RPTP CD45 in immune cell signaling is well known, but those of most other PTPs remain poorly understood. Here, we review the mechanism of action, regulation, and physiological functions of NRPTPs in immune cell signaling. Such an analysis indicates that PTPs are as important as PTKs in regulating the immune system.
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Affiliation(s)
- Lily I Pao
- Cancer Biology Program, Division of Hematology-Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
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77
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Zhao Y, Conze DB, Hanover JA, Ashwell JD. Tumor necrosis factor receptor 2 signaling induces selective c-IAP1-dependent ASK1 ubiquitination and terminates mitogen-activated protein kinase signaling. J Biol Chem 2007; 282:7777-82. [PMID: 17220297 DOI: 10.1074/jbc.m609146200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
TRAF2 and ASK1 play essential roles in tumor necrosis factor alpha (TNF-alpha)-induced mitogen-activated protein kinase signaling. Stimulation through TNF receptor 2 (TNFR2) leads to TRAF2 ubiquitination and subsequent proteasomal degradation. Here we show that TNFR2 signaling also leads to selective ASK1 ubiquitination and degradation in proteasomes. c-IAP1 was identified as the ubiquitin protein ligase for ASK1 ubiquitination, and studies with primary B cells from c-IAP1 knock-out animals revealed that c-IAP1 is required for TNFR2-induced TRAF2 and ASK1 degradation. Moreover, in the absence of c-IAP1 TNFR2-mediated p38 and JNK activation was prolonged. Thus, the ubiquitin protein ligase activity of c-IAP1 is responsible for regulating the duration of TNF signaling in primary cells expressing TNFR2.
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Affiliation(s)
- Yongge Zhao
- Laboratory of Immune Cell Biology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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