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Multipoint binding of the SLP-76 SH2 domain to ADAP is critical for oligomerization of SLP-76 signaling complexes in stimulated T cells. Mol Cell Biol 2013; 33:4140-51. [PMID: 23979596 DOI: 10.1128/mcb.00410-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The adapter molecules SLP-76 and LAT play central roles in T cell activation by recruiting enzymes and other adapters into multiprotein complexes that coordinate highly regulated signal transduction pathways. While many of the associated proteins have been characterized, less is known concerning the mechanisms of assembly for these dynamic and potentially heterogeneous signaling complexes. Following T cell receptor (TCR) stimulation, SLP-76 is found in structures called microclusters, which contain many signaling complexes. Previous studies showed that a mutation to the SLP-76 C-terminal SH2 domain nearly abolished SLP-76 microclusters, suggesting that the SH2 domain facilitates incorporation of signaling complexes into microclusters. S. C. Bunnell, A. L. Singer, D. I. Hong, B. H. Jacque, M. S. Jordan, M. C. Seminario, V. A. Barr, G. A. Koretzky, and L. E. Samelson, Mol. Cell. Biol., 26:7155-7166, 2006). Using biophysical methods, we demonstrate that the adapter, ADAP, contains three binding sites for SLP-76, and that multipoint binding to ADAP fragments oligomerizes the SLP-76 SH2 domain in vitro. These results were complemented with confocal imaging and functional studies of cells expressing ADAP with various mutations. Our results demonstrate that all three binding sites are critical for SLP-76 microcluster assembly, but any combination of two sites will partially induce microclusters. These data support a model whereby multipoint binding of SLP-76 to ADAP facilitates the assembly of SLP-76 microclusters. This model has implications for the regulation of SLP-76 and LAT microclusters and, as a result, T cell signaling.
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2
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Abstract
Developing short peptides into useful probes and therapeutic leads remains a difficult challenge. Structural rigidification is a proven method for improving the properties of short peptides. In this work, we report a strategy for stabilizing peptide macrocycles by introducing side-chain-to-side-chain staples to produce peptide bicycles with higher affinity, selectivity, and resistance to degradation. We have applied this strategy to G1, an 11-residue peptide macrocycle that binds the Src homology 2 (SH2) domain of growth-factor-bound protein 2 (Grb2). Several homodetic peptide bicycles were synthesized entirely on-resin with high yields. Two rounds of iterative design produced peptide bicycle BC1, which is 60 times more potent than G1 and 200 times more selective. Moreover, BC1 is completely intact after 24 hours in buffered human serum, conditions under which G1 is completely degraded. Our peptide-bicycle approach holds promise for the development of selective inhibitors of SH2 domains and other phosophotyrosine (pTyr)-binding proteins, as well as inhibitors of many other protein-protein interactions.
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Affiliation(s)
- Justin S. Quartararo
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Pianpian Wu
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
| | - Joshua A. Kritzer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford MA 02155 USA, Fax: (617) 627-3443
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3
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Jiang S, Liao C, Bindu L, Yin B, Worthy KW, Fisher RJ, Burke TR, Nicklaus MC, Roller PP. Discovery of thioether-bridged cyclic pentapeptides binding to Grb2-SH2 domain with high affinity. Bioorg Med Chem Lett 2009; 19:2693-8. [PMID: 19362470 DOI: 10.1016/j.bmcl.2009.03.134] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 03/06/2009] [Accepted: 03/26/2009] [Indexed: 10/21/2022]
Abstract
Blocking the interaction between phosphotyrosine (pTyr)-containing activated receptors and the Src homology 2 (SH2) domain of the growth factor receptor-bound protein 2 (Grb 2) is considered to be an effective and non-cytotoxic strategy to develop new anti-proliferate agents due to its potential to shut down the Ras activation pathway. In this study, a series of phosphotyrosine containing cyclic pentapeptides were designed and synthesized based upon the phage library derived cyclopeptide, G1TE. A comprehensive SAR study was also carried out to develop potent Grb2-SH2 domain antagonists based upon this novel template. With both the peptidomimetic optimization of the amino acid side-chains and the constraint of the backbone conformation guided by molecular modeling, we developed several potent antagonists with low micromolar range binding affinity, such as cyclic peptide 15 with an K(d)=0.359microM, which is providing a novel template for the development of Grb2-SH2 domain antagonists as potential therapeutics for certain cancers.
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Affiliation(s)
- Sheng Jiang
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, PR China.
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4
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Spuches AM, Argiros HJ, Lee KH, Haas LL, Pero SC, Krag DN, Roller PP, Wilcox DE, Lyons BA. Calorimetric investigation of phosphorylated and non-phosphorylated peptide ligand binding to the human Grb7-SH2 domain. J Mol Recognit 2007; 20:245-52. [PMID: 17705331 DOI: 10.1002/jmr.834] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Grb7 is a member of the Grb7 family of proteins, which also includes Grb10 and Grb14. All three proteins have been found to be overexpressed in certain cancers and cancer cell lines. In particular, Grb7 (along with the receptor tyrosine kinase erbB2) is overexpressed in 20-30% of breast cancers. In general, growth factor receptor bound (Grb) proteins bind to activated membrane-bound receptor tyrosine kinases (RTKs; e.g., the epidermal growth factor receptor, EGFR) through their Src homology 2 (SH2) domains. In particular, Grb7 binds to erbB2 (a.k.a. EGFR2) and may be involved in cell signaling pathways that promote the formation of metastases and inflammatory responses. In previous studies, we reported the solution structure and the backbone relaxation behavior of the Grb7-SH2/erbB2 peptide complex. In this study, isothermal titration calorimetry studies have been completed by measuring the thermodynamic binding parameters of several phosphorylated and non-phosphorylated peptides representative of natural Grb7 receptor ligands as well as ligands developed through combinatorial peptide screening methods. The entirety of these calorimetric studies is interpreted in an effort to describe the specific ligand binding characteristics of the Grb7 protein.
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Affiliation(s)
- A M Spuches
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA
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Jiang S, Li P, Peach ML, Bindu L, Worthy KW, Fisher RJ, Burke TR, Nicklaus M, Roller PP. Structure-based design of potent Grb2–SH2 domain antagonists not relying on phosphotyrosine mimics. Biochem Biophys Res Commun 2006; 349:497-503. [PMID: 16945340 DOI: 10.1016/j.bbrc.2006.08.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 08/05/2006] [Indexed: 12/01/2022]
Abstract
Development of Grb2-SH2 domain antagonists is considered to be an effective and non-cytotoxic strategy to develop new antiproliferative agents because of their potential to shut down the Ras signaling pathway. We developed a concise route for the efficient synthesis of G1TE analogs on solid phase. Using this route, a series of cyclic peptides that do not rely on phosphotyrosine or its mimics were designed and synthesized based upon the phage library-derived cyclopeptide, G1TE. Considering that Gly7 plays prominent roles for G1TE binding to the Grb2-SH2 domain, we introduced different amino acids in the 7th position. The D-Ala7-containing peptide 3 demonstrates improved binding affinity by adopting favorable conformation for protein binding. This can be rationalized by molecular modeling. The optimization at the Leu2 position was also studied, and the resulting cyclopeptides exhibited remarkably improved binding affinity. Based upon these global modifications, a highly potent peptide ligand 9 was discovered with a Kd = 17 nM, evaluated by Biacore binding assay. This new analog is one of the most potent non-phosphorus-containing Grb2-SH2 antagonists reported to date. This potent peptidomimetic provides a new template for the development of non-pTyr containing Grb2-SH2 domain antagonists and acts as a chemotherapeutic lead for the treatment of erbB2-related cancer.
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Affiliation(s)
- Sheng Jiang
- Laboratory of Medicinal Chemistry, NCI, NIH, Frederick, MD 21702, USA
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Development of Grb2 SH2 Domain Signaling Antagonists: A Potential New Class of Antiproliferative Agents. Int J Pept Res Ther 2006; 12:33-48. [PMID: 19444322 PMCID: PMC2678932 DOI: 10.1007/s10989-006-9014-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2005] [Indexed: 11/24/2022]
Abstract
Aberrant signaling through protein-tyrosine kinase (PTK)-dependent pathways is associated with several proliferative diseases. Accordingly, PTK inhibitors are being developed as new approaches for the treatment of certain cancers. Growth factor receptor bound protein 2 (Grb2) is an important downstream mediator of PTK signaling that serves obligatory roles in many pathogenic processes. One of the primary functions of Grb2 is to bind to specific phosphotyrosyl (pTyr)-containing sequences through its Src homology 2 (SH2) domain. Agents that bind to the Grb2 SH2 domain and prevent its normal function could disrupt associated PTK signaling and serve as alternatives to kinase-directed inhibitors. Starting from the X-ray crystal structure of a lead peptide bound to the Grb2 SH2 domain, this review will summarize important contributions to these efforts. The presentation will be thematically arranged according to the region of peptide modified, proceeding from the N-terminus to the C-terminus, with a special section devoted to aspects of conformational constraint.
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Lung FDT, Chang CW, Chong MC, Liou CC, Li P, Peach ML, Nicklaus MC, Lou BS, Roller PP. Small nonphosphorylated Grb2-SH2 domain antagonists evaluated by surface plasmon resonance technology. Biopolymers 2005; 80:628-35. [PMID: 15660381 DOI: 10.1002/bip.20209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The growth factor receptor-binding protein-Src homology 2 (Grb2-SH2) domain plays an important role in the oncogenic Ras signal transduction pathway, which involves cell proliferation and differentiation. Therefore, the Grb2-SH2 domain has been chosen as our target for development of potential antiproliferative agents. Herein, we report the study of the inhibitory effects of small nonphosphorylated peptide analogs interacting with the Grb2-SH2 domain protein by surface plasmon resonance (SPR) technology. A set of 8 related peptide analogs were synthesized, purified, and characterized. Their inhibitory effects on Grb2-SH2 were evaluated by the SPR technology developed with the BIACORE X instrument. The lead peptide, Fmoc-Glu-Tyr-Aib-Asn-NH2 (Fmoc-E-Y-Aib-N; Fmoc: 9-fluorenylmethyoxycarbonyl; Aib=alpha-amino isobutyric acid) inhibited Grb2-SH2 domain function with an IC50 value of 8.7 microM. A molecular modeling study of the lead peptide indicated that the glutamate in the Fmoc peptide is ideally positioned to form a strong salt bridge to Arg 67 in the Grb2-SH2 domain, using both its backbone carbonyl and its acidic group. Residue Glu 89 in Grb2-SH2 flips inward to fill the binding site and partially replace the phosphate group as a hydrogen-bond acceptor. Results of these studies provide important information for further development of potent nonphosphorylated peptide inhibitors of the Grb2-SH2 domain.
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Affiliation(s)
- Feng-Di T Lung
- Department of Chemistry, Tunghai University, Taichung, Taiwan, Republic of China.
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Machida K, Mayer BJ. The SH2 domain: versatile signaling module and pharmaceutical target. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1747:1-25. [PMID: 15680235 DOI: 10.1016/j.bbapap.2004.10.005] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 09/29/2004] [Accepted: 10/11/2004] [Indexed: 10/26/2022]
Abstract
The Src homology 2 (SH2) domain is the most prevalent protein binding module that recognizes phosphotyrosine. This approximately 100-amino-acid domain is highly conserved structurally despite being found in a wide variety proteins. Depending on the nature of neighboring protein module(s), such as catalytic domains and other protein binding domains, SH2-containing proteins play many different roles in cellular protein tyrosine kinase (PTK) signaling pathways. Accumulating evidence indicates SH2 domains are highly versatile and exhibit considerable flexibility in how they bind to their ligands. To illustrate this functional versatility, we present three specific examples: the SAP, Cbl and SOCS families of SH2-containing proteins, which play key roles in immune responses, termination of PTK signaling, and cytokine responses. In addition, we highlight current progress in the development of SH2 domain inhibitors designed to antagonize or modulate PTK signaling in human disease. Inhibitors of the Grb2 and Src SH2 domains have been extensively studied, with the aim of targeting the Ras pathway and osteoclastic bone resorption, respectively. Despite formidable difficulties in drug design due to the lability and poor cell permeability of negatively charged phosphorylated SH2 ligands, a variety of structure-based strategies have been used to reduce the size, charge and peptide character of such ligands, leading to the development of high-affinity lead compounds with potent cellular activities. These studies have also led to new insights into molecular recognition by the SH2 domain.
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Affiliation(s)
- Kazuya Machida
- Raymond and Beverly Sackler Laboratory of Genetics and Molecular Medicine, Department of Genetics and Developmental Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030-3301, USA.
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9
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Song YL, Roller PP, Long YQ. Development of l-3-aminotyrosine suitably protected for the synthesis of a novel nonphosphorylated hexapeptide with low-nanomolar Grb2-SH2 domain-binding affinity. Bioorg Med Chem Lett 2004; 14:3205-8. [PMID: 15149676 DOI: 10.1016/j.bmcl.2004.03.103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 03/29/2004] [Accepted: 03/31/2004] [Indexed: 11/30/2022]
Abstract
Synthesis of orthogonally protected (2S)-2-amino-3-(3-amino-4-hydroxy-phenyl)-propionic acid (10) suitable for solid phase peptide synthesis and its first use for the preparation of nonphosphorylated Grb2-SH2 domain antagonists (4a-c) are reported. The 3-aminotyrosine containing sulfoxide-cyclized hexapeptide (4b) exhibited potent Grb2-SH2 domain binding affinity with IC50 = 50 nM, which represents the highest affinity yet reported for a peptide inhibitor against Grb2-SH2 domain with only 6 residues free of phosphotyrosine or phosphotyrosine mimics. This potent small peptidomimetic 4b may be representative of a new class of therapeutically relevant Grb2-SH2 domain-directed agents, and acts as a chemotherapeutic lead for the treatment of erbB2-related cancers.
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Affiliation(s)
- Yan-Li Song
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, CAS, 555 Zuchongzhi Road, Shanghai 201203, China
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10
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Smith AH, Vrtis JM, Kodadek T. The Potential Of Protein-Detecting MicroArrays For Clinical Diagnostics. Adv Clin Chem 2004; 38:217-38. [PMID: 15521193 DOI: 10.1016/s0065-2423(04)38007-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Alexandra H Smith
- Department of Internal Medicine and Molecular Biology, Center for Biomedical Inventions, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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