3pfv: Difference between revisions

[[http://www.uniprot.org/uniprot/CBLB_HUMAN CBLB_HUMAN]] E3 ubiquitin-protein ligase which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes, and transfers it to substrates, generally promoting their degradation by the proteasome. Negatively regulates TCR (T-cell receptor), BCR (B-cell receptor) and FCER1 (high affinity immunoglobulin epsilon receptor) signal transduction pathways. In naive T-cells, inhibits VAV1 activation upon TCR engagement and imposes a requirement for CD28 costimulation for proliferation and IL-2 production. Also acts by promoting PIK3R1/p85 ubiquitination, which impairs its recruitment to the TCR and subsequent activation. In activated T-cells, inhibits PLCG1 activation and calcium mobilization upon restimulation and promotes anergy. In B-cells, acts by ubiquitinating SYK and promoting its proteasomal degradation. May also be involved in EGFR ubiquitination and internalization.<ref>PMID:10022120</ref> <ref>PMID:10086340</ref> <ref>PMID:11087752</ref> <ref>PMID:11526404</ref> [[http://www.uniprot.org/uniprot/EGFR_HUMAN EGFR_HUMAN]] Receptor tyrosine kinase binding ligands of the EGF family and activating several signaling cascades to convert extracellular cues into appropriate cellular responses. Known ligands include EGF, TGFA/TGF-alpha, amphiregulin, epigen/EPGN, BTC/betacellulin, epiregulin/EREG and HBEGF/heparin-binding EGF. Ligand binding triggers receptor homo- and/or heterodimerization and autophosphorylation on key cytoplasmic residues. The phosphorylated receptor recruits adapter proteins like GRB2 which in turn activates complex downstream signaling cascades. Activates at least 4 major downstream signaling cascades including the RAS-RAF-MEK-ERK, PI3 kinase-AKT, PLCgamma-PKC and STATs modules. May also activate the NF-kappa-B signaling cascade. Also directly phosphorylates other proteins like RGS16, activating its GTPase activity and probably coupling the EGF receptor signaling to the G protein-coupled receptor signaling. Also phosphorylates MUC1 and increases its interaction with SRC and CTNNB1/beta-catenin.<ref>PMID:7657591</ref> <ref>PMID:11602604</ref> <ref>PMID:12873986</ref> <ref>PMID:10805725</ref> <ref>PMID:11116146</ref> <ref>PMID:11483589</ref> <ref>PMID:17115032</ref> <ref>PMID:21258366</ref> <ref>PMID:12297050</ref> <ref>PMID:12620237</ref> <ref>PMID:15374980</ref> <ref>PMID:19560417</ref> <ref>PMID:20837704</ref>   Isoform 2 may act as an antagonist of EGF action.<ref>PMID:7657591</ref> <ref>PMID:11602604</ref> <ref>PMID:12873986</ref> <ref>PMID:10805725</ref> <ref>PMID:11116146</ref> <ref>PMID:11483589</ref> <ref>PMID:17115032</ref> <ref>PMID:21258366</ref> <ref>PMID:12297050</ref> <ref>PMID:12620237</ref> <ref>PMID:15374980</ref> <ref>PMID:19560417</ref> <ref>PMID:20837704</ref>

[[3pfv]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PFV OCA].  

 

[[Category: Human]]