Q07014

FUNCTION: Non-receptor tyrosine-protein kinase that transmits signals from cell surface receptors and plays an important role in the regulation of innate and adaptive immune responses, hematopoiesis, responses to growth factors and cytokines, integrin signaling, but also responses to DNA damage and genotoxic agents. Functions primarily as negative regulator, but can also function as activator, depending on the context. Required for the initiation of the B-cell response, but also for its down- regulation and termination. Plays an important role in the regulation of B-cell differentiation, proliferation, survival and apoptosis, and is important for immune self-tolerance. Acts downstream of several immune receptors, including the B-cell receptor, CD79A, CD79B, CD5, CD19, CD22, FCER1, FCGR2, FCGR1A, TLR2 and TLR4. Plays a role in the inflammatory response to bacterial lipopolysaccharide. Mediates the responses to cytokines and growth factors in hematopoietic progenitors, platelets, erythrocytes, and in mature myeloid cells, such as dendritic cells, neutrophils and eosinophils. Acts downstream of EPOR, KIT, MPL, the chemokine receptor CXCR4, as well as the receptors for IL3, IL5 and CSF2. Plays an important role in integrin signaling. Regulates cell proliferation, survival, differentiation, migration, adhesion, degranulation, and cytokine release. Down- regulates signaling pathways by phosphorylation of immunoreceptor tyrosine-based inhibitory motifs (ITIM), that then serve as binding sites for phosphatases, such as PTPN6/SHP-1, PTPN11/SHP-2 and INPP5D/SHIP-1, that modulate signaling by dephosphorylation of kinases and their substrates. Phosphorylates LIME1 in response to CD22 activation. Phosphorylates BTK, CBL, CD5, CD19, CD72, CD79A, CD79B, CSF2RB, DOK1, HCLS1, LILRB3/PIR-B, MS4A2/FCER1B, PTK2B/PYK2, SYK and TEC. Promotes phosphorylation of SIRPA, PTPN6/SHP-1, PTPN11/SHP-2 and INPP5D/SHIP-1. Required for rapid phosphorylation of FER in response to FCER1 activation. Mediates KIT phosphorylation. Acts as an effector of EPOR (erythropoietin receptor) in controlling KIT expression and may play a role in erythroid differentiation during the switch between proliferation and maturation. Depending on the context, activates or inhibits several signaling cascades. Regulates phosphatidylinositol 3- kinase activity and AKT1 activation. Regulates activation of the MAP kinase signaling cascade, including activation of MAP2K1/MEK1, MAPK1/ERK2, MAPK3/ERK1, MAPK8/JNK1 and MAPK9/JNK2. Mediates activation of STAT5A and/or STAT5B (By similarity). Phosphorylates LPXN on 'Tyr-72' (By similarity). CATALYTIC ACTIVITY: ATP + a [protein]-L-tyrosine = ADP + a [protein]-L-tyrosine phosphate. ENZYME REGULATION: Subject to autoinhibition, mediated by intramolecular interactions between the SH2 domain and the C- terminal phosphotyrosine. Phosphorylation at Tyr-397 is required for optimal activity. Phosphorylated by CSK at Tyr-508; phosphorylation at Tyr-508 inhibits kinase activity. Kinase activity is modulated by dephosphorylation by PTPRC/CD45. SUBUNIT: Interacts with TEC. Interacts (via SH2 domain) with FLT3 (tyrosine phosphorylated). Interacts with LIME1 and with CD79A upon activation of the B-cell antigen receptor. Interacts with the B-cell receptor complex. Interacts with phosphorylated THEMIS2. Interacts with EPOR. Interacts with MS4A2/FCER1B. Interaction (via the SH2 and SH3 domains) with MUC1 is stimulated by IL7 and the subsequent phosphorylation increases the binding between MUC1 and CTNNB1/beta-catenin. Interacts with ADAM15. Interacts with NDFIP2 and more weakly with NDFIP1. Interacts with FASLG. Interacts with KIT. Interacts with HCLS1. Interacts with FCGR2B. Interacts with FCGR1A; the interaction may be indirect. Interacts with CD19, CD22, CD79A and CD79B. Interacts (via SH3 domain) with PPP1R15A and PDE4A. Interacts with TGFB1I1. Interacts (via SH3 domain) with PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase; this interaction enhances phosphatidylinositol 3-kinase activity. Interacts with CSF2RB, the common subunit of the IL3, IL5 and CSF2 receptors. Interacts with PAG1; identified in a complex with PAG1 and STAT3. Interacts with ABL1. Interacts with PTPN6/SHP-1. Interacts (via SH3 domain) with SCIMP (via prolin-rich region) (By similarity). Interacts with LPXN (via LD motif 3) and the interaction is induced upon B-cell antigen receptor (BCR) activation (By similarity). Interacts (via ankyrin repeat region) with LYN (via SH3-domain) in an activation-independent status of LYN (By similarity). Forms a multiprotein complex with LYN and HS1 (By similarity). SUBCELLULAR LOCATION: Cell membrane (By similarity). Nucleus (By similarity). Cytoplasm (By similarity). Cytoplasm, perinuclear region (By similarity). Golgi apparatus (By similarity). Note=Accumulates in the nucleus by inhibition of Crm1-mediated nuclear export. Nuclear accumulation is increased by inhibition of its kinase activity. The trafficking from the Golgi apparatus to the cell membrane occurs in a kinase domain-dependent but kinase activity independent manner and is mediated by exocytic vesicular transport (By similarity). ALTERNATIVE PRODUCTS: Event=Alternative splicing; Named isoforms=2; Name=LYN A; IsoId=Q07014-1; Sequence=Displayed; Name=LYN B; IsoId=Q07014-2; Sequence=VSP_005004; TISSUE SPECIFICITY: Detected in spleen (at protein level). Expressed predominantly in B-lymphoid and myeloid cells. DOMAIN: The protein kinase domain plays an important role in its localization in the cell membrane (By similarity). PTM: Ubiquitinated. Ubiquitination is SH3-dependent (By similarity). PTM: Phosphorylated on tyrosine residues in response to KIT signaling (By similarity). Autophosphorylated. Phosphorylation at Tyr-397 is required for optimal activity. Phosphorylation at Tyr- 508 inhibits kinase activity. Phosphorylated at Tyr-508 by CSK. Dephosphorylated by PTPRC/CD45. Becomes rapidly phosphorylated upon activation of the B-cell receptor and the immunoglobulin receptor FCGR1A (By similarity). SIMILARITY: Belongs to the protein kinase superfamily. Tyr protein kinase family. SRC subfamily. SIMILARITY: Contains 1 protein kinase domain. SIMILARITY: Contains 1 SH2 domain. SIMILARITY: Contains 1 SH3 domain. GENE SYNONYMS:Lyn. COPYRIGHT: Protein annotation is derived from the UniProt Consortium (http://www.uniprot.org/). Distributed under the Creative Commons Attribution-NoDerivs License., SEQUENCE 512 AA; 58660 MW; E03615E229CD43F1 CRC64;

LYN_RAT

urn:biopax:ModificationFeature:LYN_RAT_1, urn:biopax:ModificationFeature:LYN_RAT_10, urn:biopax:ModificationFeature:LYN_RAT_11, urn:biopax:ModificationFeature:LYN_RAT_12, urn:biopax:ModificationFeature:LYN_RAT_13, urn:biopax:ModificationFeature:LYN_RAT_14, urn:biopax:ModificationFeature:LYN_RAT_15, urn:biopax:ModificationFeature:LYN_RAT_2, urn:biopax:ModificationFeature:LYN_RAT_3, urn:biopax:ModificationFeature:LYN_RAT_4, urn:biopax:ModificationFeature:LYN_RAT_5, urn:biopax:ModificationFeature:LYN_RAT_6, urn:biopax:ModificationFeature:LYN_RAT_7, urn:biopax:ModificationFeature:LYN_RAT_8, urn:biopax:ModificationFeature:LYN_RAT_9

MGCIKSKRKDNLNDDGVDMKTQPVRNTDRTIYVRDPTSNKQQRPVPESQLLPGQRFQAKDPEEQGDIVVALYPYDGIHPDDLSFKKGEKMKVLEEHGEWWKAKSLSSKREGFIPSNYVAKVNTLETEEWFFKDITRKDAERQLLAPGNSAGAFLIRESETLKGSFSLSVRDYDPMHGDVIKHYKIRSLDNGGYYISPRITFPCISDMIKHYQKQSDGLCRRLEKACISPKPQKPWDKDAWEIPRESIKLVKKLGAGQFGEVWMGYYNNSTKVAVKTLKPGTMSAQAFLEEANLMKTLQHDKLVRLYAVVTKEEPIYIITEFMAKGSLLDFLKSDEGSKVLLPKLIDFSAQIAEGMAYIERKNYIHRDLRAANVLVSESLMCKIADFGLARVIEDNEYTAREGAKFPIKWTAPEAINFGCFTIKSDVWSFGILLYEIVTYGKIPYPGRTNADVMTALSQGYRMPRMENCPDELYDIMKMCWKESAEERPTFDYLQSVLDDFYTATEGQYQQQP