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Zhao X, Qian W, Hou S, Wu Y, Guo H, Xu J, Zhang D, Li J, Fu R, Xu M, Wang F. Development of a reliable cell-based reporter gene assay to measure the bioactivity of anti-HER2 therapeutic antibodies. J Pharm Biomed Anal 2024; 245:116185. [PMID: 38723556 DOI: 10.1016/j.jpba.2024.116185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 04/23/2024] [Accepted: 04/25/2024] [Indexed: 05/23/2024]
Abstract
Human epidermal growth factor receptor 2 (HER2) is a key player in the pathogenesis and progression of breast cancer and is currently a primary target for breast cancer immunotherapy. Bioactivity determination is necessary to guarantee the safety and efficacy of therapeutic antibodies targeting HER2. Nevertheless, currently available bioassays for measuring the bioactivity of anti-HER2 mAbs are either not representative or have high variability. Here, we established a reliable reporter gene assay (RGA) based on T47D-SRE-Luc cell line that expresses endogenous HER2 and luciferase controlled by serum response element (SRE) to measure the bioactivity of anti-HER2 antibodies. Neuregulin-1 (NRG-1) can lead to the heterodimerization of HER2 on the cell membrane and induce the expression of downstream SRE-controlled luciferase, while pertuzumab can dose-dependently reverse the reaction, resulting in a good dose-response curve reflecting the activity of the antibody. After optimizing the relevant assay parameters, the established RGA was fully validated based on ICH-Q2 (R1), which demonstrated that the method had excellent specificity, accuracy, precision, linearity, and stability. In summary, this robust and innovative bioactivity determination assay can be applied in the development and screening, release control, biosimilar assessment and stability studies of anti-HER2 mAbs.
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Affiliation(s)
- Xiang Zhao
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252000, China
| | - Weizhu Qian
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China.
| | - Sheng Hou
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China
| | - Yimei Wu
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China
| | - Huaizu Guo
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China
| | - Jin Xu
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China
| | - Dapeng Zhang
- State Key Laboratory of Antibody Medicine and Targeted Therapy, Shang Hai 200120, China
| | - Jun Li
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252000, China
| | - Rongrong Fu
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252000, China
| | - Mengjiao Xu
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252000, China
| | - Fugui Wang
- Laboratory of Drug Discovery and Design, School of Pharmaceutical Sciences, Liaocheng University, Liaocheng 252000, China
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Gao J, Li A, Fujii S, Huang F, Nakatomi C, Nakamura I, Honda H, Kiyoshima T, Jimi E. p130Cas is required for androgen-dependent postnatal development regulation of submandibular glands. Sci Rep 2023; 13:5144. [PMID: 36991029 PMCID: PMC10060253 DOI: 10.1038/s41598-023-32390-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 03/27/2023] [Indexed: 03/31/2023] Open
Abstract
Salivary glands develop through epithelial-mesenchymal interactions and are formed through repeated branching. The Crk-associated substrate protein (p130Cas) serves as an adapter that forms a complex with various proteins via integrin and growth factor signaling, with important regulatory roles in several essential cellular processes. We found that p130Cas is expressed in ductal epithelial cells of the submandibular gland (SMG). We generated epithelial tissue-specific p130Cas-deficient (p130CasΔepi-) mice and aimed to investigate the physiological role of p130Cas in the postnatal development of salivary glands. Histological analysis showed immature development of granular convoluted tubules (GCT) of the SMG in male p130CasΔepi- mice. Immunofluorescence staining showed that nuclear-localized androgen receptors (AR) were specifically decreased in GCT cells in p130CasΔepi- mice. Furthermore, epidermal growth factor-positive secretory granules contained in GCT cells were significantly reduced in p130CasΔepi- mice with downregulated AR signaling. GCTs lacking p130Cas showed reduced numbers and size of secretory granules, disrupted subcellular localization of the cis-Golgi matrix protein GM130, and sparse endoplasmic reticulum membranes in GCT cells. These results suggest that p130Cas plays a crucial role in androgen-dependent GCT development accompanied with ER-Golgi network formation in SMG by regulating the AR signaling.
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Affiliation(s)
- Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Aonan Li
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Shinsuke Fujii
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Dento-Craniofacial Development and Regeneration Research Center Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Fei Huang
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Chihiro Nakatomi
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu, 803-8580, Japan
| | - Ichiro Nakamura
- Department of Rehabilitation, Yugawara Hospital, Japan Community Health Care Organization, 2-21-6 Chuo, Yugawara, Ashigara-shimo, Kanagawa, 259-0396, Japan
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Institute of Laboratory Animals, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Eijiro Jimi
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
- Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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3
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Yi SJ, Hwang SY, Oh MJ, Kim K, Jhun BH. Carboxy-terminal domain of Cas differentially modulates c-Jun expression, DNA synthesis, and membrane ruffling induced by insulin, EGF, and IGF-1. Anim Cells Syst (Seoul) 2018; 22:69-75. [PMID: 30460082 PMCID: PMC6138344 DOI: 10.1080/19768354.2018.1447013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/25/2018] [Accepted: 02/18/2018] [Indexed: 12/23/2022] Open
Abstract
p130 Crk-associated substrate (Cas) is an adaptor protein associating with many other signaling proteins and regulates a various biological processes including cell adhesion, migration, and growth factor stimulation. However, the exact functional role of Cas in growth factor signaling pathway was poorly understood. Here we investigated the role of Cas and its domains in the effects of insulin, EGF, and IGF-1 on c-Jun gene expression, DNA synthesis, cytoskeletal reorganization. We found that microinjection of anti-Cas antibody and C-terminal domain of Cas (Cas-CT) specifically inhibited EGF-induced, but not insulin- or IGF-1-induced, c-Jun expression. Cell cycle progression and cytoskeleton reorganization induced by insulin and EGF, but not by IGF-1, were inhibited by microinjected anti-Cas and Cas-CT. In contrast, microinjection of the substate domain (Cas-SD) of Cas did not have any inhibitory effects. These results revealed that the Cas-CT is differentially implicated in insulin and EGF-mediated, but not IGF-1-mediated, c-Jun expression, DNA synthesis and membrane ruffling.
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Affiliation(s)
- Sun-Ju Yi
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Seong Yun Hwang
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Myung-Ju Oh
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
| | - Kyunghwan Kim
- School of Biological Sciences, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Byung H Jhun
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
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Deneka A, Korobeynikov V, Golemis EA. Embryonal Fyn-associated substrate (EFS) and CASS4: The lesser-known CAS protein family members. Gene 2015; 570:25-35. [PMID: 26119091 DOI: 10.1016/j.gene.2015.06.062] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 06/23/2015] [Indexed: 01/15/2023]
Abstract
The CAS (Crk-associated substrate) adaptor protein family consists of four members: CASS1/BCAR1/p130Cas, CASS2/NEDD9/HEF1/Cas-L, CASS3/EFS/Sin and CASS4/HEPL. While CAS proteins lack enzymatic activity, they contain specific recognition and binding sites for assembly of larger signaling complexes that are essential for cell proliferation, survival, migration, and other processes. All family members are intermediates in integrin-dependent signaling pathways mediated at focal adhesions, and associate with FAK and SRC family kinases to activate downstream effectors regulating the actin cytoskeleton. Most studies of CAS proteins to date have been focused on the first two members, BCAR1 and NEDD9, with altered expression of these proteins now appreciated as influencing disease development and prognosis for cancer and other serious pathological conditions. For these family members, additional mechanisms of action have been defined in receptor tyrosine kinase (RTK) signaling, estrogen receptor signaling or cell cycle progression, involving discrete partner proteins such as SHC, NSP proteins, or AURKA. By contrast, EFS and CASS4 have been less studied, although structure-function analyses indicate they conserve many elements with the better-known family members. Intriguingly, a number of recent studies have implicated these proteins in immune system function, and the pathogenesis of developmental disorders, autoimmune disorders including Crohn's disease, Alzheimer's disease, cancer and other diseases. In this review, we summarize the current understanding of EFS and CASS4 protein function in the context of the larger CAS family group.
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Affiliation(s)
- Alexander Deneka
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, United States; Kazan Federal University, 420000, Kazan, Russian Federation
| | - Vladislav Korobeynikov
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, United States; Novosibirsk State University, Medical Department, 630090, Novosibirsk, Russian Federation
| | - Erica A Golemis
- Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, 19111, United States.
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Choi YH, Han Y, Lee SH, Jin YH, Bahn M, Hur KC, Yeo CY, Lee KY. Cbl-b and c-Cbl negatively regulate osteoblast differentiation by enhancing ubiquitination and degradation of Osterix. Bone 2015; 75:201-9. [PMID: 25744063 DOI: 10.1016/j.bone.2015.02.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 02/23/2015] [Accepted: 02/24/2015] [Indexed: 11/28/2022]
Abstract
E3 ubiquitin ligase Cbl-b and c-Cbl play important roles in bone formation and maintenance. Cbl-b and c-Cbl regulate the activity of various receptor tyrosine kinases and intracellular protein tyrosine kinases mainly by regulating the degradation of target proteins. However, the precise mechanisms of how Cbl-b and c-Cbl regulate osteoblast differentiation are not well known. In this study, we investigated potential targets of Cbl-b and c-Cbl. We found that Cbl-b and c-Cbl inhibit BMP2-induced osteoblast differentiation in mesenchymal cells. Among various osteogenic transcription factors, we identified that Cbl-b and c-Cbl suppress the protein stability and transcriptional activity of Osterix. Our results suggest that Cbl-b and c-Cbl inhibit the function of Osterix by enhancing the ubiquitin-proteasome-mediated degradation of Osterix. Taken together, we propose novel regulatory roles of Cbl-b and c-Cbl during osteoblast differentiation in which Cbl-b and c-Cbl regulate the degradation of Osterix through the ubiquitin-proteasome pathway.
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Affiliation(s)
- You Hee Choi
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Younho Han
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Sung Ho Lee
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Yun-Hye Jin
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Minjin Bahn
- Department of Life Science and Global Top5 Research Program, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Kyu Chung Hur
- Department of Life Science and Global Top5 Research Program, Ewha Womans University, Seoul 120-750, Republic of Korea
| | - Chang-Yeol Yeo
- Department of Life Science and Global Top5 Research Program, Ewha Womans University, Seoul 120-750, Republic of Korea.
| | - Kwang Youl Lee
- College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Gwangju 500-757, Republic of Korea.
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Miao Y, Wang L, Liu Y, Li AL, Liu SL, Cao HY, Zhang XP, Jiang GY, Liu D, Wang EH. Overexpression and cytoplasmic accumulation of Hepl is associated with clinicopathological parameters and poor prognosis in non-small cell lung cancer. Tumour Biol 2012; 34:107-14. [PMID: 23001926 DOI: 10.1007/s13277-012-0517-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 09/05/2012] [Indexed: 01/04/2023] Open
Abstract
Hepl, first described in 2008, is the fourth member of the Crk-associated substrate (CAS) family and is specifically expressed in the lung. Compared to other CAS proteins, Hepl has a varying effect on cell migration in different cell types. We speculated that Hepl may play a role in lung cancer invasion and metastasis. We quantified the expression and subcellular localization of Hepl in 143 non-small cell lung cancer (NSCLC) tissues, adjacent noncancerous tissues, and eight lung cancer cell lines using Western blotting, immunohistochemistry, and immunofluorescent staining. Expression of Hepl was correlated with the clinicopathological features of NSCLC. Hepl was overexpressed in 72.3 % (103/143) of the NSCLC tissues, compared to the adjacent noncancerous lung tissues (P = 0.022). Overexpression of Hepl was associated with lymph node metastasis and high TNM stage (P = 0.005 and P = 0.045, respectively). Kaplan-Meier survival curves and the log-rank test indicated that overexpression of Hepl correlated with poorer overall survival in NSCLC (P < 0.001), and Cox regression analysis demonstrated that overexpression of Hepl was an independent prognostic factor in NSCLC. Furthermore, cytoplasmic accumulation of Hepl was observed in a high metastatic potential lung cancer cell lines (H1299 and BE1), but not in low metastatic potential cell lines (LTE and A549). This study reveals that Hepl is overexpressed in the nucleus and aberrantly accumulates in the cytoplasm of NSCLC cells, and indicates that Hepl may play a role in the progression of lung cancer, including lymph node metastasis and TNM stage. Additionally, Hepl may be a useful prognostic factor in lung cancer.
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Affiliation(s)
- Yuan Miao
- Department of Pathology, The First Affiliated Hospital and College of Basic Medical Sciences, China Medical University, Shenyang, China
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Serrels A, McLeod K, Canel M, Kinnaird A, Graham K, Frame MC, Brunton VG. The role of focal adhesion kinase catalytic activity on the proliferation and migration of squamous cell carcinoma cells. Int J Cancer 2011; 131:287-97. [PMID: 21823119 DOI: 10.1002/ijc.26351] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 07/20/2011] [Indexed: 11/11/2022]
Abstract
Focal adhesion kinase (FAK) is upregulated in several epithelial tumours and there has been considerable interest in developing small molecule kinase inhibitors of FAK. However, FAK also has important adaptor functions within the cell, integrating signals from both integrins and growth factors. To investigate the role of FAKs kinase domain, we generated fak-deficient squamous cell carcinoma (SCC) cell lines. Re-expression of a wild type or kinase dead FAK allowed us to delineate its kinase dependent functions. In addition, we used the novel FAK kinase inhibitor PF-562,271. The kinase activity of FAK was important for tumour cell migration and polarity but more striking was its requirement for the anchorage independent 3 dimensional (3D) proliferation of SCC cells and their growth as xenografts in mice. Inhibition of FAK activity and prevention of growth in 3D correlated with Src inhibition. We further identified a mechanism whereby FAK regulates proliferation in 3D via regulation of the kinase activity of Src. This was dependent on the kinase activity of FAK and its resulting phosphorylation on Y397 that provides a high affinity binding site for Src. These data support the further development of FAK kinase inhibitors as agents that have the potential to inhibit both tumour cell migration and proliferation.
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Affiliation(s)
- Alan Serrels
- Edinburgh Cancer Research Centre, Institute for Genetics & Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
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8
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Han B, Xiao H, Xu J, Lodyga M, Bai XH, Jin T, Liu M. Actin filament associated protein mediates c-Src related SRE/AP-1 transcriptional activation. FEBS Lett 2011; 585:471-7. [PMID: 21236256 DOI: 10.1016/j.febslet.2011.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 12/26/2010] [Accepted: 01/03/2011] [Indexed: 10/18/2022]
Abstract
AFAP is an adaptor protein involved in cytoskeletal organization and intracellular signaling. AFAP binds and activates c-Src; however, the downstream signals of this interaction remain unknown. Here we show that co-expression of AFAP and c-Src induce transcriptional activation of SRE and AP-1 in a c-Src activity dependent fashion. Structural-functional studies suggest that the proline-rich motif in the N-terminus of AFAP is critical for c-Src activation, and subsequent SRE/AP-1 transactivation and the actin-binding domain in the AFAP C-terminus is negatively involved in the regulation of AFAP/c-Src mediated SRE/AP-1 transactivation. Selective deletion of this domain enhances transactivation of SRE. We conclude that in addition to its role in the regulation of cytoskeletal structures, AFAP may also be involved in the c-Src related transcriptional activities.
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Affiliation(s)
- Bing Han
- Division of Cellular and Molecular Biology, University Health Network Toronto General Research Institute, Toronto, Ontario, Canada
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Tikhmyanova N, Little JL, Golemis EA. CAS proteins in normal and pathological cell growth control. Cell Mol Life Sci 2010; 67:1025-48. [PMID: 19937461 PMCID: PMC2836406 DOI: 10.1007/s00018-009-0213-1] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 11/03/2009] [Accepted: 11/09/2009] [Indexed: 12/20/2022]
Abstract
Proteins of the CAS (Crk-associated substrate) family (BCAR1/p130Cas, NEDD9/HEF1/Cas-L, EFS/SIN and CASS4/HEPL) are integral players in normal and pathological cell biology. CAS proteins act as scaffolds to regulate protein complexes controlling migration and chemotaxis, apoptosis, cell cycle, and differentiation, and have more recently been linked to a role in progenitor cell function. Reflecting these complex functions, over-expression of CAS proteins has now been strongly linked to poor prognosis and increased metastasis in cancer, as well as resistance to first-line chemotherapeutics in multiple tumor types including breast and lung cancers, glioblastoma, and melanoma. Further, CAS proteins have also been linked to additional pathological conditions including inflammatory disorders, Alzheimer's and Parkinson's disease, as well as developmental defects. This review will explore the roles of the CAS proteins in normal and pathological states in the context of the many mechanistic insights into CAS protein function that have emerged in the past decade.
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Affiliation(s)
- Nadezhda Tikhmyanova
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
- Department of Biochemistry, Drexel University Medical School, Philadelphia, PA 19102 USA
| | - Joy L. Little
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
| | - Erica A. Golemis
- Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111 USA
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Giehl K, Graness A, Goppelt-Struebe M. The small GTPase Rac-1 is a regulator of mesangial cell morphology and thrombospondin-1 expression. Am J Physiol Renal Physiol 2007; 294:F407-13. [PMID: 18045834 DOI: 10.1152/ajprenal.00093.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Thrombospondin-1 (TSP-1), which is synthesized by mesangial cells, is known for its anti-angiogenic activity and its ability to activate latent TGF-beta. TSP-1 is upregulated in renal diseases associated with tissue remodeling. Therefore, we hypothesized that the expression of TSP-1 might be modulated by changes in cell morphology involving proteins of the Rho family. Spreading of mesangial cells after detachment and reseeding was characterized by the formation of lamellipodia and focal adhesions, pointing toward a Rac-1-mediated rearrangement of actin structures. Clustering of focal adhesion proteins was also observed in a model system of nocodazole-induced disruption of microtubules. These morphological alterations were impeded by pharmacological inhibition of Src family kinases, of the small GTPase Rac-1, or by downregulation of Rac-1 by siRNA. Upon cell spreading, TSP-1 was upregulated in the absence and much more prominently in the presence of serum, but also after nocodazole treatment. TSP-1 upregulation was controlled by activation of Src family kinases, ERK 1/2 and Rac-1, whereas activation of RhoA-ROCK signaling was not linked to TSP-1 induction. We thus provide evidence that TSP-1 expression is induced by common signaling pathways, which are activated by morphological alterations of renal mesangial cells or by soluble factors as contained in serum, and these pathways include Src family kinases, ERK 1/2 and Rac-1. Our data suggest that tissue remodeling activates gene expression of pathophysiologically relevant proteins such as TSP-1.
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Affiliation(s)
- Klaudia Giehl
- Institute of Pharmacology and Toxicology, University of Ulm Medical Center, Ulm, Germany
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Yadav SS, Miller WT. Cooperative activation of Src family kinases by SH3 and SH2 ligands. Cancer Lett 2007; 257:116-23. [PMID: 17719722 PMCID: PMC2045694 DOI: 10.1016/j.canlet.2007.07.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 07/06/2007] [Accepted: 07/10/2007] [Indexed: 11/21/2022]
Abstract
Src family nonreceptor tyrosine kinases are kept in a repressed state by intramolecular interactions involving the SH3 and SH2 domains of the enzymes. Ligands for these domains can displace the intramolecular associations and activate the kinases. Here, we carried out in vitro activation experiments with purified, down-regulated hematopoietic cell kinase (Hck), a Src family kinase. We show that SH3 and SH2 ligands act cooperatively to activate Src family kinases: the presence of one ligand lowers the concentration of the second ligand necessary for activation. To confirm the findings in intact cells, we studied Cas, a Src substrate that possesses SH2 and SH3 ligands. In contrast to wild-type Cas, mutant forms of Cas lacking the SH3 or SH2 ligands were unable to stimulate Src autophosphorylation when expressed in Cas-deficient fibroblasts. Cells expressing the Cas mutants also showed decreased amounts of activated Src at focal adhesions. The results suggest that proteins containing ligands for both SH3 and SH2 domains can produce a synergistic activation of Src family kinases.
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Affiliation(s)
| | - W. Todd Miller
- * To whom correspondence should be addressed: Dept. of Physiology and Biophysics, Basic Science Tower, T-6, School of Medicine, SUNY at Stony Brook, Stony Brook, NY 11794-8661, Tel.: 631-444-3533; Fax: 631-444-3432, E-mail:
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12
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Xu J, Bai XH, Lodyga M, Han B, Xiao H, Keshavjee S, Hu J, Zhang H, Yang BB, Liu M. XB130, a Novel Adaptor Protein for Signal Transduction. J Biol Chem 2007; 282:16401-12. [PMID: 17412687 DOI: 10.1074/jbc.m701684200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adaptor proteins are important mediators in signal transduction. In the present study, we report the cloning and characterization of a novel adaptor protein, XB130. This gene is located on human chromosome 10q25.3 and encodes a protein of 818 amino acids. It contains several Src homology (SH)2- and SH3-binding motifs, two pleckstrin homology domains, a coiled-coil region, and a number of potential tyrosine or serine/threonine phosphorylation sites. Endogenous XB130 interacts with c-Src tyrosine kinase. Their co-expression in COS-7 cells resulted in activation of c-Src and elevated tyrosine phosphorylation of multiple proteins, including XB130 itself. XB130 expression in HEK293 cells enhanced serum response element- and AP-1-dependent transcriptional activation mediated by c-Src. XB130DeltaN, an N-terminal deletion mutant lacking a putative SH3-binding motif and several putative SH2-binding sites, reduced its ability to mediate Src signal transduction. Down-regulation of endogenous XB130 with siRNA reduced c-Src activity, IL-8 production, EGF-induced phosphorylation of Akt and GSK3beta, and altered cell cycles in human lung epithelial cells. These data suggest that XB130 as an adaptor may play an important role in the regulation of signal transduction and cellular functions.
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Affiliation(s)
- Jing Xu
- Division of Cellular and Molecular Biology, University Health Network Toronto General Research Institute, and Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
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13
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Biswas MHU, Hasegawa HH, Rahman MA, Huang P, Mon NN, Ruhul Amin ARM, Senga T, Kannagi R, Hamaguchi M. SHP-2-Erk signaling regulates Concanavalin A-dependent production of TIMP-2. Biochem Biophys Res Commun 2006; 348:1145-9. [PMID: 16904070 DOI: 10.1016/j.bbrc.2006.07.173] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Accepted: 07/28/2006] [Indexed: 11/22/2022]
Abstract
To search for the signaling critical for the production of tissue inhibitor of metalloproteinase-2 (TIMP-2), we investigated the role of SHP-2 in TIMP-2 production with Concanavalin A (Con A)-treated cells. In wild-type fibroblasts, Con A-treatment dramatically activated TIMP-2 production. In contrast, production of TIMP-2 in response to Con A-treatment was severely impaired in cells expressing mutant SHP-2 whose 65 amino acids in the SH2-N domain were deleted. Con A-treatment activated dual signaling pathways, Erk and p38, in a SHP-2-dependent manner. Pretreatment of wild-type cells with U0126, a potent inhibitor of MEK1, significantly inhibited the production of TIMP-2, whereas SB203580, a specific inhibitor for p38, could not. Finally, expression of exogenous wild-type SHP-2 in SHP-2 mutant cells clearly rescued Erk activation and TIMP-2 production in response to Con A-treatment. Taken together, our results strongly suggest that SHP-2 plays a critical role as a positive modulator for the production of TIMP-2 via MEK1-Erk signaling in fibroblasts.
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Affiliation(s)
- Md Helal Uddin Biswas
- Department of Cancer Biology, Nagoya University School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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14
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Graness A, Cicha I, Goppelt-Struebe M. Contribution of Src-FAK signaling to the induction of connective tissue growth factor in renal fibroblasts. Kidney Int 2006; 69:1341-9. [PMID: 16531982 DOI: 10.1038/sj.ki.5000296] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Expression of connective tissue growth factor (CTGF) is sensitive to reorganization of the actin cytoskeleton, but also to alterations in cell morphology due to extracellular forces, for example, cyclic stretching or mechanical loading. Dynamic alterations of focal adhesion proteins were thus proposed to modulate CTGF induction. Immortalized human renal fibroblasts were cultured in or on top of preformed collagen-1 gels. Proteins were detected by immunofluorescence and quantified by Western blotting. Fibroblasts cultured in/on collagen gels resembled cells in vivo by their spindle-like morphology, absence of actin stress fibers, small punctiform focal contacts, and low levels of CTGF expression. Disassembly of microtubules by short-term treatment with colchicine induced cell rounding, cortical recruitment of patchy F-actin, reorganization of focal contacts into strong clusters, and upregulation of CTGF, all of which were dependent on RhoA-Rho-kinase signaling. Clustering of focal adhesion sites activated Src-family kinases and focal adhesion kinase (FAK). Interference with Src activity by PP2 had no effect on the morphological alterations but decreased tyrosine phosphorylation of focal adhesion proteins and almost completely prevented upregulation of CTGF. Furthermore, inhibition of phosphatidylinositol 3-kinase reduced CTGF expression. On the other hand, when the fibroblasts were cultured on a rigid matrix, that is collagen-coated plates, strong focal complexes prevented the dynamic alterations, and RhoA-mediated upregulation of CTGF expression was independent of Src-FAK signaling. Assembly of focal adhesion proteins regulates CTGF expression, providing a link between actin network, adhesion receptors, and CTGF-mediated functions such as synthesis of extracellular matrix proteins.
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Affiliation(s)
- A Graness
- Department of Nephrology, University of Erlangen-Nuremberg, Erlangen, Germany
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15
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Pugacheva EN, Golemis EA. HEF1-aurora A interactions: points of dialog between the cell cycle and cell attachment signaling networks. Cell Cycle 2006; 5:384-91. [PMID: 16479169 PMCID: PMC2547350 DOI: 10.4161/cc.5.4.2439] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Regulated timing of cell division cycles, and geometrical precision in the planar orientation of cell division, are critical during organismal development and remain important for the maintenance of polarized structures in adults. Mounting evidence suggests that these processes are coordinated at the centrosome through the action of proteins that mediate both cell cycle and cell attachment. Our recent work identifying HEF1 as an activator of the Aurora A kinase suggests a novel hub for such integrated signaling. We suggest that defects in components of the machinery specifying the temporal and spatial integration of cell division may induce cancer and other diseases through pleiotropic effects on cell migration, proliferation, apoptosis, and genomic stability.
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Affiliation(s)
- Elena N. Pugacheva
- Division of Basic Science, Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111
| | - Erica A. Golemis
- Division of Basic Science, Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111
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16
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Pugacheva EN, Golemis EA. The focal adhesion scaffolding protein HEF1 regulates activation of the Aurora-A and Nek2 kinases at the centrosome. Nat Cell Biol 2005; 7:937-46. [PMID: 16184168 PMCID: PMC2652766 DOI: 10.1038/ncb1309] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2005] [Accepted: 09/07/2005] [Indexed: 12/17/2022]
Abstract
Although HEF1 has a well-defined role in integrin-dependent attachment signalling at focal adhesions, it relocalizes to the spindle asters at mitosis. We report here that overexpression of HEF1 causes an increase in centrosome numbers and multipolar spindles, resembling defects induced by manipulation of the mitotic regulatory kinase Aurora-A (AurA). We show that HEF1 associates with and controls activation of AurA. We also show that HEF1 depletion causes centrosomal splitting, mono-astral spindles and hyperactivation of Nek2, implying additional action earlier in the cell cycle. These results provide new insight into the role of an adhesion protein in coordination of cell attachment and division.
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Affiliation(s)
| | - Erica A. Golemis
- * corresponding author: Erica Golemis, W406, Fox Chase Cancer Center, 333 Cottman Ave., Philadelphia, PA 19111, Phone: 215-728-2860, Fax: 215-728-3616,
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17
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Ambrogio C, Voena C, Manazza AD, Piva R, Riera L, Barberis L, Costa C, Tarone G, Defilippi P, Hirsch E, Boeri Erba E, Mohammed S, Jensen ON, Palestro G, Inghirami G, Chiarle R. p130Cas mediates the transforming properties of the anaplastic lymphoma kinase. Blood 2005; 106:3907-16. [PMID: 16105984 PMCID: PMC1895100 DOI: 10.1182/blood-2005-03-1204] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Translocations of the anaplastic lymphoma kinase (ALK) gene have been described in anaplastic large-cell lymphomas (ALCLs) and in stromal tumors. The most frequent translocation, t(2;5), generates the fusion protein nucleophosmin (NPM)-ALK with intrinsic tyrosine kinase activity. Along with transformation, NPM-ALK induces morphologic changes in fibroblasts and lymphoid cells, suggesting a direct role of ALK in cell shaping. In this study, we used a mass-spectrometry-based proteomic approach to search for proteins involved in cytoskeleton remodeling and identified p130Cas (p130 Crk-associated substrate) as a novel interactor of NPM-ALK. In 293 cells and in fibroblasts as well as in human ALK-positive lymphoma cell lines, NPM-ALK was able to bind p130Cas and to induce its phosphorylation. Both of the effects were dependent on ALK kinase activity and on the adaptor protein growth factor receptor-bound protein 2 (Grb2), since no binding or phosphorylation was found with the kinase-dead mutant NPM-ALK(K210R) or in the presence of a Grb2 dominant-negative protein. Phosphorylation of p130Cas by NPM-ALK was partially independent from Src (tyrosine kinase pp60c-src) kinase activity, as it was still detectable in Syf-/- cells. Finally, p130Cas-/- (also known as Bcar1-/-) fibroblasts expressing NPM-ALK showed impaired actin filament depolymerization and were no longer transformed compared with wild-type cells, indicating an essential role of p130Cas activation in ALK-mediated transformation.
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Affiliation(s)
- Chiara Ambrogio
- Center for Experimental Research and Medical Studies and Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy
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18
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Niihori T, Aoki Y, Ohashi H, Kurosawa K, Kondoh T, Ishikiriyama S, Kawame H, Kamasaki H, Yamanaka T, Takada F, Nishio K, Sakurai M, Tamai H, Nagashima T, Suzuki Y, Kure S, Fujii K, Imaizumi M, Matsubara Y. Functional analysis of PTPN11/SHP-2 mutants identified in Noonan syndrome and childhood leukemia. J Hum Genet 2005; 50:192-202. [PMID: 15834506 DOI: 10.1007/s10038-005-0239-7] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2004] [Accepted: 01/25/2005] [Indexed: 10/25/2022]
Abstract
Noonan syndrome (NS) is characterized by short stature, characteristic facial features, and heart defects. Recently, missense mutations of PTPN11, the gene encoding protein tyrosine phosphatase (PTP) SHP-2, were identified in patients with NS. Further, somatic mutations in PTPN11 were detected in childhood leukemia. Recent studies showed that the phosphatase activities of five mutations identified in NS and juvenile myelomonocytic leukemia (JMML) were increased. However, the functional properties of the other mutations remain unidentified. In this study, in order to clarify the differences between the mutations identified in NS and leukemia, we examined the phosphatase activity of 14 mutants of SHP-2. We identified nine mutations, including a novel F71I mutation, in 16 of 41 NS patients and two mutations, including a novel G503V mutation, in three of 29 patients with leukemia. Immune complex phosphatase assays of individual mutants transfected in COS7 cells showed that ten mutants identified in NS and four mutants in leukemia showed 1.4-fold to 12.7-fold increased activation compared with wild-type SHP-2. These results suggest that the pathogenesis of NS and leukemia is associated with enhanced phosphatase activity of mutant SHP-2. A comparison of the phosphatase activity in each mutant and a review of previously reported cases showed that high phosphatase activity observed in mutations at codons 61, 71, 72, and 76 was significantly associated with leukemogenesis.
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Affiliation(s)
- Tetsuya Niihori
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Sendai, 980-8574, Japan
| | - Yoko Aoki
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Sendai, 980-8574, Japan.
| | - Hirofumi Ohashi
- Division of Medical Genetics, Saitama Children's Medical Center, Saitama, Japan
| | - Kenji Kurosawa
- Division of Medical Genetics, Kanagawa Children's Medical Center, Yokohama, Japan
| | - Tatsuro Kondoh
- Department of Pediatrics, Nagasaki University of Medicine, Nagasaki, Japan
| | - Satoshi Ishikiriyama
- Division of Clinical Genetics and Cytogenetics, Shizuoka Children's Hospital, Shizuoka, Japan
| | - Hiroshi Kawame
- Division of Medical Genetics, Nagano Children's Hospital, Nagano, Japan
| | - Hotaka Kamasaki
- Department of Pediatrics, Sapporo Medical University, Sapporo, Japan
| | | | - Fumio Takada
- Department of Medical Genetics, Kitasato University Graduate School of Medical Sciences, Sagamihara, Japan
| | - Kimio Nishio
- Department of Pediatrics, Seirei Hamamatsu General Hospital, Hamamatsu, Japan
| | - Masahiro Sakurai
- Department of Cardiovascular Surgery, Tohoku University School of Medicine, Sendai, Japan
| | - Hiroshi Tamai
- Department of Pediatrics, Osaka Medical College, Osaka, Japan
| | | | - Yoichi Suzuki
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Sendai, 980-8574, Japan
| | - Shigeo Kure
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Sendai, 980-8574, Japan
| | - Kunihiro Fujii
- Department of Pediatrics, Tohoku University School of Medicine, Sendai, Japan
| | - Masue Imaizumi
- Department of Hematology and Oncology, Miyagi Children's Hospital, Sendai, Japan
| | - Yoichi Matsubara
- Department of Medical Genetics, Tohoku University School of Medicine, 1-1 Seiryo-machi, Sendai, 980-8574, Japan
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19
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Sandilands E, Cans C, Fincham VJ, Brunton VG, Mellor H, Prendergast GC, Norman JC, Superti-Furga G, Frame MC. RhoB and actin polymerization coordinate Src activation with endosome-mediated delivery to the membrane. Dev Cell 2005; 7:855-69. [PMID: 15572128 DOI: 10.1016/j.devcel.2004.09.019] [Citation(s) in RCA: 187] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2004] [Revised: 08/27/2004] [Accepted: 09/30/2004] [Indexed: 10/26/2022]
Abstract
We have used a c-Src-GFP fusion protein to address the spatial control of Src activation and the nature of Src-associated intracellular structures during stimulus-induced transit to the membrane. Src is activated during transit, particularly in RhoB-containing cytoplasmic endosomes associated with the perinuclear recycling compartment. Knocking out RhoB or expressing a dominant-interfering Rab11 mutant suppresses both catalytic activation of Src and translocation of active kinase to peripheral membrane structures. In addition, the Src- and RhoB-containing endosomes harbor proteins involved in actin polymerization and filament assembly, for example Scar1, and newly polymerized actin can associate with these endosomes in a Src-dependent manner. This implies that Src may regulate an endosome-associated actin nucleation activity. In keeping with this, Src controls the actin dependence of RhoB endosome movement toward the plasma membrane. This work identifies RhoB as a component of "outside-in" signaling pathways that coordinate Src activation with translocation to transmembrane receptors.
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Affiliation(s)
- Emma Sandilands
- The Beatson Institute for Cancer Research, Cancer Research UK Beatson Laboratories, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD, United Kingdom
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20
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Samarakoon R, Higgins CE, Higgins SP, Kutz SM, Higgins PJ. Plasminogen activator inhibitor type-1 gene expression and induced migration in TGF-β1-stimulated smooth muscle cells is pp60c-src/MEK-dependent. J Cell Physiol 2005; 204:236-46. [PMID: 15622520 DOI: 10.1002/jcp.20279] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Transforming growth factor-beta1 (TGF-beta1) stimulates expression of plasminogen activator inhibitor type-1 (PAI-1), a serine protease inhibitor (SERPIN) important in the control of stromal barrier proteolysis and cell-to-matrix adhesion. Pharmacologic agents that target MEK (PD98059, U0126) or src family (PP1) kinases attenuated TGF-beta1-dependent PAI-1 transcription in R22 aortic smooth muscle cells. Pretreatment with PP1 at concentrations that inhibited TGF-beta1-dependent PAI-1 expression also blocked ERK1/2 activation/nuclear accumulation suggesting that the required src kinase activity is upstream of ERK1/2 in the TGF-beta1-initiated signaling cascade. The IC(50) of the PP1-sensitive kinase, furthermore, specifically implied involvement of pp60(c-src) in PAI-1 induction. Indeed, addition of TGF-beta1 to quiescent R22 cells resulted in a 3-fold increase in pp60(c-src) autophosphorylation and kinase activity. Transfection of a dominant-negative pp60(c-src) construct, moreover, reduced TGF-beta1-induced PAI-1 expression levels to that of unstimulated controls or PP1-pretreated cells. A >/=170 kDa protein that co-immunoprecipitated with TGF-beta1-activated pp60(c-src) was also phosphorylated transiently in response to TGF-beta1. TGF-beta1 is known to transactivate the 170 kDa EGF receptor (EGFR) by autocrine HB-EGF or TGF-alpha mechanisms suggesting involvement of EGFR activation in certain TGF-beta1-initiated responses. Incubation of quiescent R22 cells with the EGFR-specific inhibitor AG1478 prior to growth factor (EGF or TGF-beta1) addition effectively blocked EGFR activation as determined by direct visualization of receptor internalization. AG1478 suppressed (in a dose-dependent fashion) EGF-induced PAI-1 protein levels and, at a final concentration of 2.5 muM, virtually eliminated EGF-dependent PAI-1 synthesis. More importantly, AG1478 similarly repressed inducible PAI-1 levels in TGF-beta1-stimulated R22 cultures. PP1, PD98059, and U0126 also inhibited TGF-beta1-dependent cell motility at concentrations that significantly attenuated PAI-1 expression. Consistent with the AG1478-associated reductions in EGF- and TGF-beta1-stimulated PAI-1 expression, pretreatment of R22 cell cultures with AG1478 effectively suppressed growth factor-stimulated cell motility. These data indicate that two major phenotypic characteristics of TGF-beta1-exposure (i.e., transcription of specific target genes [e.g., PAI-1], increased cell motility) are linked in the R22 vascular smooth muscle cell system, require pp60(c-src) kinase activity and MEK signaling and involve activation of an AG1478-sensitive (likely EGFR-dependent) pathway.
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Affiliation(s)
- Rohan Samarakoon
- Center for Cell Biology & Cancer Research, Albany Medical College, Albany, New York, USA
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21
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Goldberg GS, Alexander DB, Pellicena P, Zhang ZY, Tsudal H, Miller WT. Src phosphorylates Cas on tyrosine 253 to promote migration of transformed cells. J Biol Chem 2003; 278:46533-40. [PMID: 12972425 PMCID: PMC2441571 DOI: 10.1074/jbc.m307526200] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cas is a member of the focal adhesion complex. Phosphorylation of Cas by Src is an important event leading to cell transformation. Using mass spectrometry, we have mapped 11 sites in Cas that are phosphorylated by Src. These sites are all located between residues 132 and 414 of Cas, in a region that is required for binding to a number of other proteins including Crk. We tested synthetic peptides modeled on Cas phosphorylation sites, and found that the sequence containing tyrosine 253 was phosphorylated by Src most efficiently. Using cells derived from Cas-deficient mice, we confirmed that Cas greatly enhanced the ability of Src to transform cells. Phosphorylation of Cas on tyrosine 253 was not required for Src to increase growth rate, suppress contact inhibition, or suppress anchorage dependence. Yet, in contrast to these growth characteristics, phosphorylation of Cas on tyrosine 253 was required for Src to promote cell migration. Thus, a single phosphorylation site on this focal adhesion adaptor protein can effectively separate cell migration from other transformed growth characteristics.
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Affiliation(s)
- Gary S. Goldberg
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8661
- To whom correspondence may be addressed: Dept. of Physiology and Biophysics, School of Medicine, Basic Science Tower T6, Health Science Complex, State University of New York at Stony Brook, Stony Brook, NY 11794-8661. Tel.: 631-444-3533; Fax: 631-444-3432; E-mail: or
| | - David B. Alexander
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8661
| | - Patricia Pellicena
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8661
| | - Zhong-Yin Zhang
- Department of Molecular Pharmacology, College of Medicine, Albert Einstein University, Bronx, New York 10461
| | - Hiroyuki Tsudal
- Division of Experimental Pathology and Chemotherapy, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
| | - W. Todd Miller
- Department of Physiology and Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, New York 11794-8661
- To whom correspondence may be addressed: Dept. of Physiology and Biophysics, School of Medicine, Basic Science Tower T6, Health Science Complex, State University of New York at Stony Brook, Stony Brook, NY 11794-8661. Tel.: 631-444-3533; Fax: 631-444-3432; E-mail: or
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22
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Samarakoon R, Higgins PJ. Pp60c-src mediates ERK activation/nuclear localization and PAI-1 gene expression in response to cellular deformation. J Cell Physiol 2003; 195:411-20. [PMID: 12704650 DOI: 10.1002/jcp.10247] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Release of transcellular tension upon disruption of actin stress fibers with cytochalasin D (CD) and associated changes in cell morphology are reflected in the rapid transcription of "deformation-responsive" genes. For certain genes (e.g., urokinase plasminogen activator and its type-1 inhibitor PAI-1), de novo mRNA synthesis appears to require cell shape-dependent activation of the MAP kinases ERK1/2. ERK activation in response to microfilament disruption was inhibited completely by the broad-spectrum tyrosine kinase inhibitor genistein and the relatively src-kinase selective compound PP1. Such inhibitor sensitivity profiles suggested that src-family members, likely pp60(c-src), were important upstream elements in deformation-related ERK activation. pp60(c-src) kinase activity was elevated fourfold within 15 min after CD addition to quiescent R22 smooth muscle cells and declined quickly thereafter. CD-induced increases in the phosphorylation levels of both pp60(c-src) and IgG heavy chain (a substrate target in the coupled immunoprecipitation/in vitro pp60(c-src) kinase assay) were ablated completely by pretreatment with the src-type kinase inhibitor PP1. Prior PP1 exposure similarly repressed CD-stimulated PAI-1 transcript accumulation. Consistent with the pharmacologic findings, transfection of a dominant-negative pp60(c-src) expression construct (DN-Src) effectively suppressed (in a concentration-dependent manner) CD-induced PAI-1 synthesis in R22 cells. To more specifically address the potential involvement of src kinases in CD-initiated ERK mobilization, R22 cells were transiently co-transfected with DN-Src and Myc-tagged ERK2 expression constructs, serum-deprived then stimulated with CD. The effect of DN-Src expression on endogenous ERK1/2 activation and nuclear translocation was assessed in separate experiments. The phosphorylation levels of both exogenous (Myc-ERK2) and endogenous ERK1/2 targets was significantly reduced by DN-Src; nuclear accumulation of pERK1/2 was completely inhibited. These data indicate that pp60(c-src) is a critical upstream activator of the ERK cascade leading to PAI-1 transcription in response to cellular deformation stimuli.
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Affiliation(s)
- Rohan Samarakoon
- Center for Cell Biology & Cancer Research, Albany Medical College, New York 12208, USA
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23
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Chan PC, Liang CC, Yu KC, Chang MC, Ho WL, Chen BH, Chen HC. Synergistic effect of focal adhesion kinase overexpression and hepatocyte growth factor stimulation on cell transformation. J Biol Chem 2002; 277:50373-9. [PMID: 12393896 DOI: 10.1074/jbc.m204691200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Although an elevated level of focal adhesion kinase (FAK) has been observed in a variety of invasive human tumors, forced expression of FAK alone in cultured cells does not cause them to exhibit transformed phenotypes. Therefore, the role of FAK in oncogenic transformation remains unclear. In this study, we have demonstrated that FAK overexpression in Madin-Darby canine kidney epithelial cells rendered them susceptible to transformation by hepatocyte growth factor (HGF). Using various FAK mutants, we found that the simultaneous bindings of Src and p130(cas) were required for FAK to potentiate cell transformation. Expression of FAK-related nonkinase, kinase-deficient Src, or the Src homology 3 domain of p130(cas), which respectively serve as dominant negative versions of FAK, Src, and p130(cas), apparently reversed the transformed phenotypes of FAK-overexpressed cells upon HGF stimulation. Moreover, FAK overexpression was able to enhance HGF-elicited signals, leading to sustained activation of ERK, JNK, and AKT, which could be prevented by the expression of the Src homology 3 domain of p130(cas). Taken together, our results indicate that the synergistic effect of FAK overexpression and HGF stimulation leads to cell transformation and implicate a critical role of p130(cas) in this process.
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Affiliation(s)
- Po-Chao Chan
- Department of Life Sciences and the Graduate Institute of Biomedical Sciences, National Chung Hsing University, Taichung 40227, Taiwan
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24
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Schmitt JM, Stork PJS. Galpha and Gbeta gamma require distinct Src-dependent pathways to activate Rap1 and Ras. J Biol Chem 2002; 277:43024-32. [PMID: 12221082 DOI: 10.1074/jbc.m204006200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The Src tyrosine kinase is necessary for activation of extracellular signal-regulated kinases (ERKs) by the beta-adrenergic receptor agonist, isoproterenol. In this study, we examined the role of Src in the stimulation of two small G proteins, Ras and Rap1, that have been implicated in isoproterenol's signaling to ERKs. We demonstrate that the activation of isoproterenol of both Rap1 and Ras requires Src. In HEK293 cells, isoproterenol activates Rap1, stimulates Rap1 association with B-Raf, and activates ERKs, all via PKA. In contrast, the activation by isoproterenol of Ras requires Gbetagamma subunits, is independent of PKA, and results in the phosphoinositol 3-kinase-dependent activation of AKT. Interestingly, beta-adrenergic stimulation of both Rap1 and ERKs, but not Ras and AKT, can be blocked by a Src mutant (SrcS17A) that is incapable of being phosphorylated and activated by PKA. Furthermore, a Src mutant (SrcS17D), which mimics PKA phosphorylation at serine 17, stimulates Rap1 activation, Rap1/B-Raf association, and ERK activation but does not stimulate Ras or AKT. These data suggest that Rap1 activation, but not that of Ras, is mediated through the direct phosphorylation of Src by PKA. We propose that the beta(2)-adrenergic receptor activates Src via two independent mechanisms to mediate distinct signaling pathways, one through Galpha(s) to Rap1 and ERKs and the other through Gbetagamma to Ras and AKT.
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Affiliation(s)
- John M Schmitt
- Vollum Institute, and the Department of Cell and Developmental Biology, Oregon Health Sciences University, Portland, Oregon 97201, USA
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25
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Kim JT, Joo CK. Involvement of cell-cell interactions in the rapid stimulation of Cas tyrosine phosphorylation and Src kinase activity by transforming growth factor-beta 1. J Biol Chem 2002; 277:31938-48. [PMID: 12065577 DOI: 10.1074/jbc.m201178200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Transforming growth factor-beta (TGF-beta) regulates a wide range of physiological and pathological cellular processes, including cell migration, mesenchymal transition, extracellular matrix synthesis, and cell death. Cas (Crk-associated substrate, 130 kDa), an adaptor protein localized at focal adhesions and stress fibers, is also known to have important functions in cell migration and the induction of immediate-early gene expression. Here, we report that a rapid and transient tyrosine phosphorylation of Cas is induced by TGF-beta 1 and that E-cadherin-mediated cell-cell interaction and the Src kinase pathway are involved in this early TGF-beta signaling. The addition of TGF-beta 1 to epithelial cells rapidly induced tyrosine phosphorylation of Cas and promoted the formation of complexes between focal adhesion molecules. Cas phosphorylation required the integrity of the actin cytoskeleton but was not dependent on cell adhesion, implying that Cas-dependent signaling may be distinct from integrin signaling. TGF-beta 1 also stimulated Src kinase activity, and specific inhibitors of Src completely blocked the induction of Cas phosphorylation by TGF-beta 1. The Cas phosphorylation and Src kinase activation seen in our results were induced in an epithelial phenotype-specific manner. Stable transfection of E-cadherin to L929 cells and L cells as well as E-cadherin blocking assay revealed that E-cadherin-mediated cell-cell interactions were essential for both Cas phosphorylation and Src kinase activation. Taken together, our data suggest that rapid Cas phosphorylation and Src kinase activation may play a novel role in TGF-beta signal transduction.
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Affiliation(s)
- Jong-Tak Kim
- Laboratory of Visual Science, College of Medicine, The Catholic University of Korea, and Catholic Research Institutes of Medical Science, Seoul 137 040, Korea
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26
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Samarakoon R, Higgins PJ. MEK/ERK pathway mediates cell-shape-dependent plasminogen activator inhibitor type 1 gene expression upon drug-induced disruption of the microfilament and microtubule networks. J Cell Sci 2002; 115:3093-103. [PMID: 12118065 DOI: 10.1242/jcs.115.15.3093] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Changes in cellular morphology induced as a consequence of direct perturbation of cytoskeletal structure with network-specific targeting agents(i.e. microfilament- or microtubule-disrupting drugs) results in the stimulated expression of a specific subset of genes. Transcription of c-fos, collagenase, transforming growth factor-β, actin,urokinase plasminogen activator and its type-1 inhibitor (PAI-1) appears to be particularly responsive to shape-activated signaling pathways. Cytochalasin D(CD) or colchicine treatment of contact-inhibited and serum-deprived vascular smooth muscle (R22) cells was used, therefore, as a model system to evaluate morphology-associated controls on PAI-1 gene regulation in the absence of added growth factors. PAI-1 transcript levels in quiescent R22 cells increased rapidly and in a CD-concentration-dependent fashion, with kinetics of expression paralleling the morphological changes. Colchicine concentrations that effectively disrupted microtubule structure and reduced the cellular`footprint' area (to approximately that of CD treatment) also stimulated PAI-1 synthesis. Shape-related increases in PAI-1 mRNA synthesis were ablated by prior exposure to actinomycin D. Unlike the mechanism of induction in growth-factor-stimulated cells, CD- and colchicine-induced PAI-1 expression required on-going protein synthesis (i.e. it was a secondary response). Although PAI-1 is a TGF-β-regulated gene and TGF-β expression is also shape dependent, an autocrine TGF-β loop was not a factor in CD-initiated PAI-1 transcription. Since CD exposure resulted in actin microfilament disruption and subsequent morphological changes, with uncertain effects on interactions between signaling intermediates or `scaffold'structures, a pharmacological approach was selected to probe the pathways involved. Signaling events leading to PAI-1 induction were compared with colchicine-treated cells. CD- as well as colchicine-stimulated PAI-1 expression was effectively and dose dependently attenuated by the MEK inhibitor PD98059 (in the 10 to 25 μM concentration range), consistent with the known MAP kinase dependency of PAI-1 synthesis in growth-factor-stimulated cells. Reduced PAI-1 mRNA levels upon exposure to genistein prior to CD addition correlated with inhibition of ERK1/2 activity, implicating a tyrosine kinase in shape-dependent MEK activation. Src-family kinases,moreover, appeared to be specific upstream elements in the CD- and colchicine-dependent pathways of PAI-1 transcription since both agents effectively activated pp60c-src kinase activity in quiescent R22 cells. The restrictive (src-family) kinase inhibitor PP1 completely inhibited induced, as well as basal, ERK activity in a coupled immunoprecipitation myelin-basic-protein-phosphorylation assay and ablated shape-initiated PAI-1 mRNA expression. These data suggest that PP1-sensitive tyrosine kinases are upstream intermediates in cell-shape-associated signaling pathways resulting in ERK1/2 activation and subsequent PAI-1 transcription. In contrast to the rapid and transient kinetics of ERK activity typical of serum-stimulated cells, the ERK1/2 response to CD and colchicine is both delayed and relatively sustained. Collectively, these data support a model in which MEK is a focal point for the convergence of shape-initiated signaling events leading to induced PAI-1 transcription.
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MESH Headings
- Actin Cytoskeleton/drug effects
- Actin Cytoskeleton/enzymology
- Animals
- Cell Size/drug effects
- Cell Size/genetics
- Cells, Cultured
- Colchicine/pharmacology
- Cytochalasin D/pharmacology
- Cytoskeleton/drug effects
- Cytoskeleton/enzymology
- Dactinomycin/pharmacology
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/genetics
- MAP Kinase Kinase 1
- MAP Kinase Signaling System/drug effects
- MAP Kinase Signaling System/physiology
- Microtubules/drug effects
- Microtubules/enzymology
- Mitogen-Activated Protein Kinase Kinases/drug effects
- Mitogen-Activated Protein Kinase Kinases/metabolism
- Mitogen-Activated Protein Kinases/drug effects
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Plasminogen Activator Inhibitor 1/biosynthesis
- Plasminogen Activator Inhibitor 1/genetics
- Protein Serine-Threonine Kinases/drug effects
- Protein Serine-Threonine Kinases/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Transcription, Genetic/drug effects
- Transcription, Genetic/genetics
- Transforming Growth Factor beta/drug effects
- Transforming Growth Factor beta/metabolism
- src-Family Kinases/drug effects
- src-Family Kinases/metabolism
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Affiliation(s)
- Rohan Samarakoon
- Center for Cell Biology and Cancer Research, Albany Medical College, Albany, New York 12208, USA
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27
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Kirsch KH, Kensinger M, Hanafusa H, August A. A p130Cas tyrosine phosphorylated substrate domain decoy disrupts v-crk signaling. BMC Cell Biol 2002; 3:18. [PMID: 12119061 PMCID: PMC117778 DOI: 10.1186/1471-2121-3-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2002] [Accepted: 07/15/2002] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The adaptor protein p130Cas (Cas) has been shown to be involved in different cellular processes including cell adhesion, migration and transformation. This protein has a substrate domain with up to 15 tyrosines that are potential kinase substrates, able to serve as docking sites for proteins with SH2 or PTB domains. Cas interacts with focal adhesion plaques and is phosphorylated by the tyrosine kinases FAK and Src. A number of effector molecules have been shown to interact with Cas and play a role in its function, including c-crk and v-crk, two adaptor proteins involved in intracellular signaling. Cas function is dependent on tyrosine phosphorylation of its substrate domain, suggesting that tyrosine phosphorylation of Cas in part regulates its control of adhesion and migration. To determine whether the substrate domain alone when tyrosine phosphorylated could signal, we have constructed a chimeric Cas molecule that is phosphorylated independently of upstream signals. RESULTS We found that a tyrosine phosphorylated Cas substrate domain acts as a dominant negative mutant by blocking Cas-mediated signaling events, including JNK activation by the oncogene v-crk in transient and stable lines and v-crk transformation. This block was the result of competition for binding partners as the chimera competed for binding to endogenous c-crk and exogenously expressed v-crk. CONCLUSION Our approach suggests a novel method to study adaptor proteins that require phosphorylation, and indicates that mere tyrosine phosphorylation of the substrate domain of Cas is not sufficient for its function.
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Affiliation(s)
- Kathrin H Kirsch
- Laboratory of Molecular Oncology, The Rockefeller University, NY, NY, 10021, USA
- Department of Biochemistry, Boston University School of Medicine, 715 Albany Street, K-225, Boston, MA 02118, USA
| | - Margaret Kensinger
- Immunology Research Laboratories, Department of Veterinary Science, Penn State University, 115 Henning Building, University Park, PA 16802, USA
| | - Hidesaburo Hanafusa
- Laboratory of Molecular Oncology, The Rockefeller University, NY, NY, 10021, USA
- Osaka Bioscience Institute, 6-2-4 Furuedai, Suita, Osaka 565-0874, Japan
| | - Avery August
- Immunology Research Laboratories, Department of Veterinary Science, Penn State University, 115 Henning Building, University Park, PA 16802, USA
- Laboratory of Molecular Oncology, The Rockefeller University, NY, NY, 10021, USA
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28
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Abstract
TFII-I is a multifunctional transcription factor that is also involved in signal transduction. Here we show that TFII-I undergoes a c-Src-dependent tyrosine phosphorylation on tyrosine residues 248 and 611 and translocates to the nucleus in response to growth factor signaling. Tyrosine-phosphorylated nuclear TFII-I activates a stably integrated c-fos reporter gene. Withdrawal of signal leads to diminution of nuclear TFII-I, suggesting that the signal-dependent translocation is reversible. Antibodies against either TFII-I or c-Src abrogate growth factor-stimulated activation of c-fos. Consistent with the notion that tyrosine phosphorylation of TFII-I is required for its transcriptional activity, phosphorylation-deficient mutants of TFII-I fail to activate the c-fos promoter. These data demonstrate that TFII-I, through a Src-dependent mechanism, reversibly translocates from the cytoplasm to the nucleus, leading to the transcriptional activation of growth-regulated genes.
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Affiliation(s)
- Venugopalan Cheriyath
- Department of Pathology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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29
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Nakamoto T, Suzuki T, Huang J, Matsumura T, Seo S, Honda H, Sakai R, Hirai H. Analysis of gene expression profile in p130(Cas)-deficient fibroblasts. Biochem Biophys Res Commun 2002; 294:635-41. [PMID: 12056816 DOI: 10.1016/s0006-291x(02)00527-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
p130(Cas) (Cas) is a docking protein that becomes tyrosine phosphorylated in v-Src- or v-Crk-transformed cells and in integrin-stimulated cells. Cas -/- fibroblasts show defects in stress fiber formation, cell spreading, cell migration, and transformation by activated Src. To further characterize the role of Cas in signaling, we compared the expression profile in Cas -/- fibroblasts with that in Cas-re-expressing fibroblasts using the microarray methods. In Cas -/- fibroblasts, the expression of heme oxygenase 1 and caveolin-1 was reduced, but the expression of procollagen 1 alpha 1, procollagen 3 alpha 1, procollagen 11 alpha 1, elastin, periostin, TSC-36, and MARCKS was enhanced. The domains in Cas necessary for the change varied among these genes. Activated Src reduced the expression of most of these genes both in Cas -/- and in Cas +/+ fibroblasts. These results suggest the existence of signaling pathways that emanate from Cas to gene expression.
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Affiliation(s)
- Tetsuya Nakamoto
- Department of Hematology and Oncology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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30
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Yang LT, Alexandropoulos K, Sap J. c-SRC mediates neurite outgrowth through recruitment of Crk to the scaffolding protein Sin/Efs without altering the kinetics of ERK activation. J Biol Chem 2002; 277:17406-14. [PMID: 11867627 DOI: 10.1074/jbc.m111902200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
SRC family kinases have been consistently and recurrently implicated in neurite extension events, yet the mechanism underlying their neuritogenic role has remained elusive. We report that epidermal growth factor (EGF) can be converted from a non-neuritogenic into a neuritogenic factor through moderate activation of endogenous SRC by receptor-protein-tyrosine phosphatase alpha (a physiological SRC activator). We show that such a qualitative change in the response to EGF is not accompanied by changes in the extent or kinetics of ERK induction in response to this factor. Instead, the pathway involved relies on increased tyrosine phosphorylation of, and recruitment of Crk to, the SRC substrate Sin/Efs. The latter is a scaffolding protein structurally similar to the SRC substrate Cas, tyrosine phosphorylation of which is critical for migration in fibroblasts and epithelial cells. Expression of a dominant negative version of Sin interfered with receptor-protein-tyrosine phosphatase alpha/EGF- as well as fibroblast growth factor-induced neurite outgrowth. These observations uncouple neuritogenic signaling in PC12 cells from sustained activation of ERK kinases and for the first time identify an effector of SRC function in neurite extension.
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Affiliation(s)
- Liang-Tung Yang
- Department of Pharmacology, New York University School of Medicine, New York, New York 10016, USA
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31
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Wang Z, Tseng CP, Pong RC, Chen H, McConnell JD, Navone N, Hsieh JT. The mechanism of growth-inhibitory effect of DOC-2/DAB2 in prostate cancer. Characterization of a novel GTPase-activating protein associated with N-terminal domain of DOC-2/DAB2. J Biol Chem 2002; 277:12622-31. [PMID: 11812785 DOI: 10.1074/jbc.m110568200] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
DOC-2/DAB2 is a member of the disable gene family with tumor-inhibitory activity. Its down-regulation is associated with several neoplasms, and serine phosphorylation of its N terminus modulates DOC-2/DAB2's inhibitory effect on AP-1 transcriptional activity. We describe the cloning of DIP1/2, a novel gene that interacts with the N-terminal domain of DOC-2/DAB2. DIP1/2 is a novel GTPase-activating protein containing a Ras GTPase-activating protein homology domain (N terminus) and two other unique domains (i.e. 10 proline repeats and leucine zipper). Interaction between DOC-2/DAB2 and DIP1/2 is detected in normal tissues such as the brain and prostate. Altered expression of these two proteins is often detected in prostate cancer cells. Indeed, the presence of DIP1/2 effectively blocks mitogen-induced gene expression and inhibits the growth of prostate cancer. Thus, DOC-2/DAB2 and DIP1/2 appear to represent a unique negative regulatory complex that maintains cell homeostasis.
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Affiliation(s)
- Zhi Wang
- Department of Urology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75390-9110, USA
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32
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Schlesinger TK, Bonvin C, Jarpe MB, Fanger GR, Cardinaux JR, Johnson GL, Widmann C. Apoptosis stimulated by the 91-kDa caspase cleavage MEKK1 fragment requires translocation to soluble cellular compartments. J Biol Chem 2002; 277:10283-91. [PMID: 11782455 DOI: 10.1074/jbc.m106885200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
MEKK1, a 196-kDa mitogen-activated protein kinase (MAPK) kinase kinase, generates anti-apoptotic signaling as a full-length protein but induces apoptosis when cleaved by caspases. Here, we show that caspase-dependent cleavage of MEKK1 relocalizes the protease-generated 91-kDa kinase fragment from a particulate fraction to a soluble cytoplasmic fraction. Relocalization of MEKK1 catalytic activity is necessary for the pro-apoptotic function of MEKK1. The addition of a membrane-targeting signal to the 91-kDa fragment inhibits caspase activation and the induction of apoptosis but does not change the activation of JNK, ERK, NFkappaB, or p300. These results identify the caspase cleavage of MEKK1 as a dynamic regulatory mechanism that alters the subcellular distribution of MEKK1, changing its function to pro-apoptotic signaling, which does not depend on the currently described MEKK1 effectors.
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Affiliation(s)
- Thomas K Schlesinger
- Institute of Cellular Biology and Morphology, University of Lausanne, 1005 Lausanne, Switzerland
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33
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Fashena SJ, Einarson MB, O'Neill GM, Patriotis C, Golemis EA. Dissection of HEF1-dependent functions in motility and transcriptional regulation. J Cell Sci 2002; 115:99-111. [PMID: 11801728 DOI: 10.1242/jcs.115.1.99] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cas-family proteins have been implicated as signaling intermediaries in diverse processes including cellular attachment, motility, growth factor response, apoptosis and oncogenic transformation. The three defined Cas-family members (p130Cas, HEF1/Cas-L and Efs/Sin) are subject to multiple forms of regulation (including cell-cycle- and cell-attachment-mediated post-translational modification and cleavage) that complicate elucidation of the function of specific Cas proteins in defined biological processes. To explore the biological role of HEF1 further, we have developed a series of cell lines in which HEF1 production is regulated by an inducible promoter. In this system, HEF1 production rapidly induces changes in cellular morphology and motility, enhancing cell speed and haptotaxis towards fibronectin in a process partially dependent on intact ERK and p38 MAPK signaling pathways. Finally, cDNA expression array analysis and subsequent studies indicate that HEF1 production increases levels of mRNA transcripts encoding proteins that are associated with motility, cell transformation and invasiveness, including several metalloproteinases, MLCK, p160ROCK and ErbB2. Upregulation of such proteins suggests mechanisms through which misregulation of HEF1 may be involved in cancer progression.
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Affiliation(s)
- Sarah J Fashena
- Fox Chase Cancer Center, 7701 Burholme Ave, Philadelphia, PA 19111, USA
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34
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Bouton AH, Riggins RB, Bruce-Staskal PJ. Functions of the adapter protein Cas: signal convergence and the determination of cellular responses. Oncogene 2001; 20:6448-58. [PMID: 11607844 DOI: 10.1038/sj.onc.1204785] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Since Cas was first identified as a highly phosphorylated 130 kilodalton protein that associated with the v-Src and v-Crk-oncoproteins, considerable effort has been made to determine its function. Its predicted role as a scaffolding molecule based on its domain structure has been largely confirmed. Through its ability to undergo rapid changes in phosphorylation, subcellular localization and association with heterologous proteins, Cas may spatially and temporally regulate the function of its binding partners. Numerous proteins have been identified that bind to Cas in vitro and/or in vivo, but in only a few cases is there an understanding of how Cas may function in these protein complexes. To date, Cas-Crk and Cas-Src complexes have been most frequently implicated in Cas function, particularly in regards to processes involving regulation of the actin cytoskeleton and proliferation. These and other Cas protein complexes contribute to the critical role of Cas in cell adhesion, migration, proliferation and survival of normal cycling cells. However, under conditions in which these processes are deregulated, Cas appears to play a role in oncogenic transformation and perhaps metastasis. Therefore, in its capacity as an adapter protein, Cas serves as a point of convergence for many distinct signaling inputs, ultimately contributing to the generation of specific cellular responses.
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Affiliation(s)
- A H Bouton
- Department of Microbiology, University of Virginia School of Medicine, Box 800734, Charlottesville, Virginia VA 22908, USA.
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35
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Benaud CM, Dickson RB. Regulation of the expression of c-Myc by beta1 integrins in epithelial cells. Oncogene 2001; 20:759-68. [PMID: 11314009 DOI: 10.1038/sj.onc.1204152] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2000] [Revised: 11/30/2000] [Accepted: 12/06/2000] [Indexed: 01/20/2023]
Abstract
Cell adhesion promotes cellular proliferation through the regulation of gene expression, including the immediate early genes. However, the precise role of cell adhesion in the regulation of the c-Myc proto-oncogene is not clear, and the adhesion-dependent signaling pathway(s) regulating the expression of c-Myc has yet to be defined. We now show that integrin signaling directly regulates the expression of c-Myc in the mammary epithelial cell line 184A1N4 (A1N4). Adhesion of quiescent A1N4 cells to fibronectin, and to collagen types IV or I, induces the expression of c-Myc in an ECM concentration-dependent fashion. Cytoskeletal rearrangement, and integrin engagement and integrin clustering are required for the induction of c-Myc by fibronectin. Furthermore, beta1 integrin function-blocking antibodies prevent the adhesion-dependent induction of c-Myc. Adhesion of A1N4 cells results in the activation both of c-Src and of the Erk 1/2 mitogen-activated protein kinase (MAPK), each of which precedes the induction of c-Myc. Pharmacological inhibitors specific for either the c-Src family of kinases or for MEK1 block the adhesion-dependent induction of c-Myc. These observations indicate that beta1 integrins regulate the expression of c-Myc through the activation of the Src family of tyrosine kinases and the MAK kinase pathway.
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Affiliation(s)
- C M Benaud
- Vincent T Lombardi Cancer Center, Georgetown University Medical Center, 3970 Reservoir Rd. NW, Washington, DC 20007, USA
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36
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Sanders MA, Basson MD. Collagen IV-dependent ERK activation in human Caco-2 intestinal epithelial cells requires focal adhesion kinase. J Biol Chem 2000; 275:38040-7. [PMID: 10986280 DOI: 10.1074/jbc.m003871200] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Integrin-initiated extracellular signal-regulated kinase (ERK) activation by matrix adhesion may require focal adhesion kinase (FAK) or be FAK-independent via caveolin and Shc. This remains controversial for fibroblast and endothelial cell adhesion to fibronectin and is less understood for other matrix proteins and cells. We investigated Caco-2 intestinal epithelial cell ERK activation by collagen I and IV, laminin, and fibronectin. Collagens or laminin, but not fibronectin, stimulated tyrosine phosphorylation of FAK, paxillin, and p130(cas) and activated ERK1/2. Shc, tyrosine-phosphorylated by matrix adhesion in many cells, was not phosphorylated in Caco-2 cells in response to any matrix. Caveolin expression did not affect Caco-2 Shc phosphorylation in response to fibronectin. FAK, ERK, and p130(cas) tyrosine phosphorylation were activated after 10-min adhesion to collagen IV. FAK activity increased for 45 min after collagen IV adhesion and persisted for 2 h, while p130(cas) phosphorylation increased only slightly after 10 min. ERK activity peaked at 10 min, declined after 30 min, and returned to base line after 1 h. Transfection with FAK-related nonkinase, but not substrate domain deleted p130(cas), strongly inhibited ERK2 activation in response to collagen IV, indicating Caco-2 ERK activation is at least partly regulated by FAK.
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Affiliation(s)
- M A Sanders
- Department of Surgery, Yale University, New Haven, Connecticut 06520-8062, USA
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37
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Xing L, Ge C, Zeltser R, Maskevitch G, Mayer BJ, Alexandropoulos K. c-Src signaling induced by the adapters Sin and Cas is mediated by Rap1 GTPase. Mol Cell Biol 2000; 20:7363-77. [PMID: 10982853 PMCID: PMC86290 DOI: 10.1128/mcb.20.19.7363-7377.2000] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Oncogenic Src proteins have been extensively studied to gain insight into the signaling mechanisms of Src. To better understand signaling through wild-type Src, we used an approach that involves activation of Src signaling through the binding of physiologic ligands to the Src SH3 domain. To this end, we used full-length and truncated versions of the multiadapter molecules Cas and Sin to activate c-Src, and we examined the intracellular pathways that mediate Src signaling under these conditions. We show that although all proteins bind to and are phosphorylated by c-Src, quantitative differences exist in the ability of the different ligands to activate c-Src signaling. In addition, we show that Sin- and Cas-induced Src signaling, as assayed by transcriptional activation, is exclusively mediated through a pathway that involves the adapter Crk and the GTP-binding protein Rap1. These data are in contrast to previous observations showing Ras to mediate signaling downstream of transforming Src alleles. In our system, we found that signaling through the oncogenic SrcY527 mutant is indeed mediated by Ras. In addition, we found that Rap1 also mediates oncogenic Src signaling. Our results show for the first time that Rap1 mediates c-Src kinase signaling and reveal mechanistic differences in the signaling properties of wild-type and transforming Src proteins.
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Affiliation(s)
- L Xing
- Department of Pharmacology, College of Physicians and Surgeons of Columbia University, New York, New York 10032, USA
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38
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Gotoh T, Cai D, Tian X, Feig LA, Lerner A. p130Cas regulates the activity of AND-34, a novel Ral, Rap1, and R-Ras guanine nucleotide exchange factor. J Biol Chem 2000; 275:30118-23. [PMID: 10896938 DOI: 10.1074/jbc.m003074200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously identified a novel murine protein, AND-34, with a carboxyl-terminal domain homologous to Ras family guanine nucleotide exchange factors (GEFs), which bound to the focal adhesion docking protein p130(Cas). Work by others has implicated both the human homologue of AND-34, BCAR3, and human p130(Cas), BCAR1, in the resistance of breast cancer cells to the anti-estrogen tamoxifen. Here we report that AND-34 displays GEF activity on RalA, Rap1A, and R-Ras but not Ha-Ras GTPases in cells. In contrast to several other Ral-GEFs, the Ral GEF activity of AND-34 is not augmented by constitutively active Ha-Ras(Val-12), consistent with the absence of a detectable Ras-binding domain. Efficient binding to AND-34 required both the Src-binding domain and a flanking carboxyl-terminal region of p130(Cas). The p130(Cas)-binding site mapped to a carboxyl-terminal sequence within the AND-34 GEF domain. Overexpression of p130(Cas), but not an AND-34-binding mutant of p130(Cas), inhibited the Ral GEF activity of co-transfected AND-34. This work identifies a new potential function for p130(Cas) and a new regulatory pathway involved in the control of Ral, Rap, and R-Ras GTPases that may participate in the progression of breast cancer cells to tamoxifen resistance.
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Affiliation(s)
- T Gotoh
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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39
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Burnham MR, Bruce-Staskal PJ, Harte MT, Weidow CL, Ma A, Weed SA, Bouton AH. Regulation of c-SRC activity and function by the adapter protein CAS. Mol Cell Biol 2000; 20:5865-78. [PMID: 10913170 PMCID: PMC86064 DOI: 10.1128/mcb.20.16.5865-5878.2000] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
SRC family kinases play essential roles in a variety of cellular functions, including proliferation, survival, differentiation, and apoptosis. The activities of these kinases are regulated by intramolecular interactions and by heterologous binding partners that modulate the transition between active and inactive structural conformations. p130(CAS) (CAS) binds directly to both the SH2 and SH3 domains of c-SRC and therefore has the potential to structurally alter and activate this kinase. In this report, we demonstrate that overexpression of full-length CAS in COS-1 cells induces c-SRC-dependent tyrosine phosphorylation of multiple endogenous cellular proteins. A carboxy-terminal fragment of CAS (CAS-CT), which contains the c-SRC binding site, was sufficient to induce c-SRC-dependent protein tyrosine kinase activity, as measured by tyrosine phosphorylation of cortactin, paxillin, and, to a lesser extent, focal adhesion kinase. A single amino acid substitution located in the binding site for the SRC SH3 domain of CAS-CT disrupted CAS-CT's interaction with c-SRC and inhibited its ability to induce tyrosine phosphorylation of cortactin and paxillin. Murine C3H10T1/2 fibroblasts that expressed elevated levels of tyrosine phosphorylated CAS and c-SRC-CAS complexes exhibited an enhanced ability to form colonies in soft agar and to proliferate in the absence of serum or growth factors. CAS-CT fully substituted for CAS in mediating growth in soft agar but was less effective in promoting serum-independent growth. These data suggest that CAS plays an important role in regulating specific signaling pathways governing cell growth and/or survival, in part through its ability to interact with and modulate the activity of c-SRC.
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Affiliation(s)
- M R Burnham
- Department of Microbiology and Cancer Center, Health Sciences Center, University of Virginia, Charlottesville, Virginia 22908, Trinity College, Dublin 2, Ireland.
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40
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Hakak Y, Hsu YS, Martin GS. Shp-2 mediates v-Src-induced morphological changes and activation of the anti-apoptotic protein kinase Akt. Oncogene 2000; 19:3164-71. [PMID: 10918571 DOI: 10.1038/sj.onc.1203655] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The protein-tyrosine phosphatase Shp-2 is a positive modulator of the Ras/mitogen-activated protein kinase pathway and a putative substrate of the transforming non-receptor tyrosine kinase v-Src. To characterize the role of Shp-2 in cellular transformation and signaling by v-Src, we expressed v-Src in normal and Shp-2-deficient mouse embryo fibroblasts. Expression of Shp-2 was found to be necessary for morphological transformation by v-Src: Shp-2+/+ cells became rounded or spindly upon v-Src expression, whereas Shp-2-deficient cells remained relatively flat. v-Src-induced reorganization of the actin cytoskeleton and the formation of podosomes were compromised in Shp-2-deficient cells. Shp-2 deficiency also reduced v-Src-induced activation of the anti-apoptotic protein kinase Akt. The reduced activation of Akt in Shp-2-deficient cells correlated with a reduction in the association of the p85 regulatory subunit of PI3-kinase with the adapter protein Cbl. Activation of PI3-kinase by v-Src may be mediated by the association of the adapter protein Cbl with the p85 subunit. Since activation of Akt is dependent on PI3-kinase, this suggests that the effect of Shp-2 on Akt activation may be mediated, at least in part, by its effects on the interaction between PI3-kinase and Cbl. The defect in activation of the Akt survival pathway also correlated with enhanced sensitivity of Shp-2-deficient cells to an apoptosis-inducing agent. These results implicate Shp-2 in v-Src-induced cytoskeletal reorganization and activation of the Akt cell survival pathway.
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Affiliation(s)
- Y Hakak
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA
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Donaldson JC, Dempsey PJ, Reddy S, Bouton AH, Coffey RJ, Hanks SK. Crk-associated substrate p130(Cas) interacts with nephrocystin and both proteins localize to cell-cell contacts of polarized epithelial cells. Exp Cell Res 2000; 256:168-78. [PMID: 10739664 DOI: 10.1006/excr.2000.4822] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Crk-associated substrate (p130(Cas), Cas) is a docking protein first recognized as having elevated phosphotyrosine content in mammalian cells transformed by v-Src and v-Crk oncoproteins. Subsequent studies have implicated Cas in the control of normal cell behavior through its roles in integrin-mediated signal transduction and organization of the actin cytoskeleton at sites of cell adhesion. In this study, we sought to gain new insight into normal Cas function by identifying previously unrecognized interacting proteins. A yeast two-hybrid screen using the C-terminal region of Cas as a bait identified the Src homology 3 (SH3) domain of the mouse "nephrocystin" protein-orthologous to a human protein whose loss of function leads to the cystic kidney disease familial juvenile nephronophthisis. The putative full-length mouse and partial canine nephrocystin sequences were deduced from cDNA clones. Additional studies using epitope-tagged mouse nephrocystin indicated that nephrocystin and Cas can interact in mammalian cells and revealed that both proteins prominently localize at or near sites of cell-cell contact in polarized Madin-Darby canine kidney epithelial cells. Our findings provide novel insight into the normal cellular activities regulated by both Cas and nephrocystin, and raise the possibility that these proteins have a related function in polarized epithelial cells.
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Affiliation(s)
- J C Donaldson
- Department of Cell Biology, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, Tennessee 37232, USA
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Abstract
Cellular morphology is determined by the organization of the intracellular actin cytoskeleton, which is influenced by external and internal cues. Focal adhesions are sites at which the actin cytoskeleton is linked to the extracellular matrix by integrin receptor complexes. In addition to providing structural tethering points for cells, integrin receptor complexes transduce signals that influence a broad range of cellular processes, including migration, proliferation, transformation and apoptosis. The Cas proteins (p130Cas, HEF1/Cas-L and Efs/Sin), a family of docking proteins containing multiple interaction domains, are important components of integrin receptor signalling and have been implicated in all of these processes.
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Affiliation(s)
- G M O'Neill
- Fox Chase Cancer Center, Division of Basic Science, 7701 Burholme Avenue, Philadelphia, PA 19111, USA
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Hakak Y, Martin GS. Cas mediates transcriptional activation of the serum response element by Src. Mol Cell Biol 1999; 19:6953-62. [PMID: 10490632 PMCID: PMC84690 DOI: 10.1128/mcb.19.10.6953] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/1999] [Accepted: 07/06/1999] [Indexed: 01/17/2023] Open
Abstract
The Src substrate p130(Cas) is a docking protein containing an SH3 domain, a substrate domain that contains multiple consensus SH2 binding sites, and a Src binding region. We have examined the possibility that Cas plays a role in the transcriptional activation of immediate early genes (IEGs) by v-Src. Transcriptional activation of IEGs by v-Src occurs through distinct transcriptional control elements such as the serum response element (SRE). An SRE transcriptional reporter was used to study the ability of Cas to mediate Src-induced SRE activation. Coexpression of v-Src and Cas led to a threefold increase in SRE-dependent transcription over the level induced by v-Src alone. Cas-dependent activation of the SRE was dependent on the kinase activity of v-Src and the Src binding region of Cas. Signaling to the SRE is promoted by a serine-rich region within Cas and inhibited by the Cas SH3 domain. Cas-dependent SRE activation was accompanied by an increase in the level of active Ras and in the activity of the mitogen-activated protein kinase (MAPK) Erk2; these changes were blocked by coexpression of dominant-negative mutants of the adapter protein Grb2. SRE activation was abrogated by coexpression of dominant-negative mutants of Ras, MAPK kinase (Mek1), and Grb2. Coexpression of Cas with v-Src enhanced the association of Grb2 with the adapter protein Shc and the protein tyrosine phosphatase Shp-2; coexpression of Shc or Shp-2 mutants significantly reduced SRE activation by Cas and v-Src. Cas-induced Grb2 association with Shp-2 and Shc may account for the Cas-dependent activation of the Ras/Mek/Erk pathway and SRE-dependent transcription. 14-3-3 proteins may also play a role in Cas-mediated signaling to the SRE. Overexpression of Cas was found to modestly enhance epidermal growth factor (EGF)-induced activation of the SRE. A Cas mutant lacking the Src binding region did not potentiate the EGF response, suggesting that Cas enhances EGF signaling by binding to endogenous cellular Src or another Src family member. These observations implicate Cas as a mediator of Src-induced transcriptional activation.
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Affiliation(s)
- Y Hakak
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, California 94720-3204, USA
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