Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1972242817 169 SYFVGQPTKDSMVYNLNTQPEGAFVIRYSESKSKCLALSMRvpcsHNPSGISHYLIIRNEQGFRLKLSaTKKPFPTLQMM 248
Cdd:cd00173     1 PWFHGSISREEAERLLRGKPDGTFLVRESSSEPGDYVLSVR----SGDGKVKHYLIERNEGGYYLLGG-SGRTFPSLPEL 75

                  ....
gi 1972242817 249 LTHH 252
Cdd:cd00173    76 VEHY 79

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1972242817 169 SYFVGQPTKDSMVYNLNTQPEGAFVIRYSESKSKCLALSMRvpcsHNPSGISHYLIIRNEQGFRLKLSaTKKPFPTLQMM 248
Cdd:cd00173     1 PWFHGSISREEAERLLRGKPDGTFLVRESSSEPGDYVLSVR----SGDGKVKHYLIERNEGGYYLLGG-SGRTFPSLPEL 75

                  ....
gi 1972242817 249 LTHH 252
Cdd:cd00173    76 VEHY 79

SH2 domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1972242817 184 LNTQPEGAFVIRYSESKSKCLALSMRVpcshnPSGISHYLIIRNEQG--FRlklsATKKPFPTLQMMLTHH 252
Cdd:pfam00017  16 LNGKPDGTFLVRESESTPGGYTLSVRD-----DGKVKHYKIQSTDNGgyYI----SGGVKFSSLAELVEHY 77

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1972242817 169 SYFVGQPTKDSMVYNLNTQPEGAFVIRYSESKSKCLALSMRvpcsHNPSGISHYLIIRNEQGFRLKLSaTKKPFPTLQMM 248
Cdd:cd00173     1 PWFHGSISREEAERLLRGKPDGTFLVRESSSEPGDYVLSVR----SGDGKVKHYLIERNEGGYYLLGG-SGRTFPSLPEL 75

                  ....
gi 1972242817 249 LTHH 252
Cdd:cd00173    76 VEHY 79

Src homology 2 domain found in Tensin-like proteins; SH2 domain found in Tensin-like proteins. The Tensins are a family of intracellular proteins that interact with receptor tyrosine kinases (RTKs), integrins, and actin. They are thought act as signaling bridges between the extracellular space and the cytoskeleton. There are four homologues: Tensin1, Tensin2 (TENC1, C1-TEN), Tensin3 and Tensin4 (cten), all of which contain a C-terminal tandem SH2-PTB domain pairing, as well as actin-binding regions that may localize them to focal adhesions. The isoforms of Tensin2 and Tensin3 contain N-terminal C1 domains, which are atypical and not expected to bind to phorbol esters. Tensins 1-3 contain a phosphatase (PTPase) and C2 domain pairing which resembles PTEN (phosphatase and tensin homologue deleted on chromosome 10) protein. PTEN is a lipid phosphatase that dephosphorylates phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) to yield phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). As PtdIns(3,4,5)P3 is the product of phosphatidylinositol 3-kinase (PI3K) activity, PTEN is therefore a key negative regulator of the PI3K pathway. Because of their PTEN-like domains, the Tensins may also possess phosphoinositide-binding or phosphatase capabilities. However, only Tensin2 and Tensin3 have the potential to be phosphatases since only their PTPase domains contain a cysteine residue that is essential for catalytic activity. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1972242817 176 TKDSMVYNLNTQPEGAFVIRYSESKSKCLALSMRV---PCSHNPSGIS---------HYLIIRNEQGFRLKLSATKKPFP 243
Cdd:cd09927    11 SRDQAIALLKDKPPGTFLVRDSTTYKGAYGLAVKVatpPPGVNPFEAKgdpeselvrHFLIEPSPKGVKLKGCPNEPVFG 90

                          90       100
                  ....*....|....*....|
gi 1972242817 244 TLQMMLTHHSVLESHLPCTL 263
Cdd:cd09927    91 SLSALVYQHSITPLALPCKL 110

SH2 domain;

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1972242817 184 LNTQPEGAFVIRYSESKSKCLALSMRVpcshnPSGISHYLIIRNEQG--FRlklsATKKPFPTLQMMLTHH 252
Cdd:pfam00017  16 LNGKPDGTFLVRESESTPGGYTLSVRD-----DGKVKHYKIQSTDNGgyYI----SGGVKFSSLAELVEHY 77

Src homology 2 (SH2) domain found in Ras and Rab interactor (RIN)-family; The RIN (AKA Ras interaction/interference) family is composed of RIN1, RIN2 and RIN3. These proteins have multifunctional domains including SH2 and proline-rich (PR) domains in the N-terminal region, and RIN-family homology (RH), VPS9 and Ras-association (RA) domains in the C-terminal region. RIN proteins function as Rab5-GEFs, and RIN3 specifically functions as a Rab31-GEF. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1972242817 184 LNTQPEGAFVIRYSeSKSKCLALSMRVPCSHNPSGISHYLIIRNEQGFRLKLSATKkpFPTLQMMLTHHSVLESHLPCT 262
Cdd:cd10339    26 LQTEPPGTFLVRKS-NTRQCQVLCMRLPEASGPAFVSEHYIKESPGGVSLEGSELM--FPDLFRLIAFYCHSRDILPFT 101

Src homology 2 (SH2) domain found in Abelson murine lymphosarcoma virus (ABL) proteins; ABL-family proteins are highly conserved tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. Several types of posttranslational modifications control ABL catalytic activity, subcellular localization, and stability, with consequences for both cytoplasmic and nuclear ABL functions. Binding partners provide additional regulation of ABL catalytic activity, substrate specificity, and downstream signaling. By combining this cassette with actin-binding and -bundling domain, ABL proteins are capable of connecting phosphoregulation with actin-filament reorganization. Vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions. ABL1 includes nuclear localization signals and a DNA binding domain which is used to mediate DNA damage-repair functions, while ABL2 has additional binding capacity for actin and for microtubules to enhance its cytoskeletal remodeling functions. SH2 is involved in several autoinhibitory mechanism that constrain the enzymatic activity of the ABL-family kinases. In one mechanism SH2 and SH3 cradle the kinase domain while a cap sequence stabilizes the inactive conformation resulting in a locked inactive state. Another involves phosphatidylinositol 4,5-bisphosphate (PIP2) which binds the SH2 domain through residues normally required for phosphotyrosine binding in the linker segment between the SH2 and kinase domains. The SH2 domain contributes to ABL catalytic activity and target site specificity. It is thought that the ABL catalytic site and SH2 pocket have coevolved to recognize the same sequences. Recent work now supports a hierarchical processivity model in which the substrate target site most compatible with ABL kinase domain preferences is phosphorylated with greatest efficiency. If this site is compatible with the ABL SH2 domain specificity, it will then reposition and dock in the SH2 pocket. This mechanism also explains how ABL kinases phosphorylates poor targets on the same substrate if they are properly positioned and how relatively poor substrate proteins might be recruited to ABL through a complex with strong substrates that can also dock with the SH2 pocket. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 1972242817 190 GAFVIRYSESKSKCLALSMRvpcshNPSGISHYLIIRNEQGfrLKLSATKKPFPTLQMMLTHHSVLESHLPCTLHF 265
Cdd:cd09935    25 GSFLVRESESSPGQYSISLR-----YDGRVYHYRISEDSDG--KVYVTQEHRFNTLAELVHHHSKNADGLITTLRY 93

Src homology 2 (SH2) domain found in Fyn isoform a like proteins; Fyn is a member of the Src non-receptor type tyrosine kinase family of proteins. This cd contains the SH2 domain found in Fyn isoform a type proteins. Fyn is involved in the control of cell growth and is required in the following pathways: T and B cell receptor signaling, integrin-mediated signaling, growth factor and cytokine receptor signaling, platelet activation, ion channel function, cell adhesion, axon guidance, fertilization, entry into mitosis, and differentiation of natural killer cells, oligodendrocytes and keratinocytes. The protein associates with the p85 subunit of phosphatidylinositol 3-kinase and interacts with the Fyn-binding protein. Alternatively spliced transcript variants encoding distinct isoforms exist. Fyn is primarily localized to the cytoplasmic leaflet of the plasma membrane. Tyrosine phosphorylation of target proteins by Fyn serves to either regulate target protein activity, and/or to generate a binding site on the target protein that recruits other signaling molecules. FYN has been shown to interact with a number of proteins including: BCAR1, Cbl, Janus kinase, nephrin, Sky, tyrosine kinase, Wiskott-Aldrich syndrome protein, and Zap-70. Fyn has a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1972242817 185 NTQPEGAFVIRYSESKSKCLALSMRVPCSHNPSGISHYLIIR-NEQGFRLklsATKKPFPTLQMMLTHHSVLESHLPCTL 263
Cdd:cd10418    22 FGNPRGTFLIRESETTKGAYSLSIRDWDDMKGDHVKHYKIRKlDNGGYYI---TTRAQFETLQQLVQHYSERAAGLCCRL 98

Src homology 2 (SH2) domain found in the Src family of non-receptor tyrosine kinases; The Src family kinases are nonreceptor tyrosine kinases that have been implicated in pathways regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. It is thought that transforming ability of Src is linked to its ability to activate key signaling molecules in these pathways, rather than through direct activity. As such blocking Src activation has been a target for drug companies. Src family members can be divided into 3 groups based on their expression pattern: 1) Src, Fyn, and Yes; 2) Blk, Fgr, Hck, Lck, and Lyn; and 3) Frk-related kinases Frk/Rak and Iyk/Bsk Of these, cellular c-Src is the best studied and most frequently implicated in oncogenesis. The c-Src contains five distinct regions: a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. Src exists in both active and inactive conformations. Negative regulation occurs through phosphorylation of Tyr, resulting in an intramolecular association between phosphorylated Tyr and the SH2 domain of SRC, which locks the protein in a closed conformation. Further stabilization of the inactive state occurs through interactions between the SH3 domain and a proline-rich stretch of residues within the kinase domain. Conversely, dephosphorylation of Tyr allows SRC to assume an open conformation. Full activity requires additional autophosphorylation of a Tyr residue within the catalytic domain. Loss of the negative-regulatory C-terminal segment has been shown to result in increased activity and transforming potential. Phosphorylation of the C-terminal Tyr residue by C-terminal Src kinase (Csk) and Csk homology kinase results in increased intramolecular interactions and consequent Src inactivation. Specific phosphatases, protein tyrosine phosphatase a (PTPa) and the SH-containing phosphatases SHP1/SHP2, have also been shown to take a part in Src activation. Src is also activated by direct binding of focal adhesion kinase (Fak) and Crk-associated substrate (Cas) to the SH2 domain. SRC activity can also be regulated by numerous receptor tyrosine kinases (RTKs), such as Her2, epidermal growth factor receptor (EGFR), fibroblast growth factor receptor, platelet-derived growth factor receptor (PDGFR), and vascular endothelial growth factor receptor (VEGFR). In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 1972242817 188 PEGAFVIRYSESKSKCLALSMRvpcSHNPSG---ISHYLIIR--NEQGFrlklSATKKPFPTLQMMLTHHS 253
Cdd:cd09933    25 PRGTFLIRESETTPGAYSLSVR---DGDDARgdtVKHYRIRKldNGGYY----ITTRATFPTLQELVQHYS 88