2ak5

Structural highlights

Function

[ARHG7_RAT] Acts as a RAC1 guanine nucleotide exchange factor (GEF) and can induce membrane ruffling. Functions in cell migration, attachment and cell spreading. Promotes targeting of RAC1 to focal adhesions. May function as a positive regulator of apoptosis. Downstream of NMDA receptors and CaMKK-CaMK1 signaling cascade, promotes the formation of spines and synapses in hippocampal neurons (By similarity). [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.^{[1] [2] [3] [4]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Rho guanine nucleotide exchange factor 3D structures

References

1. ↑ Elly C, Witte S, Zhang Z, Rosnet O, Lipkowitz S, Altman A, Liu YC. Tyrosine phosphorylation and complex formation of Cbl-b upon T cell receptor stimulation. Oncogene. 1999 Feb 4;18(5):1147-56. PMID:10022120 doi:10.1038/sj.onc.1202411
2. ↑ Ettenberg SA, Keane MM, Nau MM, Frankel M, Wang LM, Pierce JH, Lipkowitz S. cbl-b inhibits epidermal growth factor receptor signaling. Oncogene. 1999 Mar 11;18(10):1855-66. PMID:10086340 doi:10.1038/sj.onc.1202499
3. ↑ Fang D, Wang HY, Fang N, Altman Y, Elly C, Liu YC. Cbl-b, a RING-type E3 ubiquitin ligase, targets phosphatidylinositol 3-kinase for ubiquitination in T cells. J Biol Chem. 2001 Feb 16;276(7):4872-8. Epub 2000 Nov 21. PMID:11087752 doi:10.1074/jbc.M008901200
4. ↑ Fang D, Liu YC. Proteolysis-independent regulation of PI3K by Cbl-b-mediated ubiquitination in T cells. Nat Immunol. 2001 Sep;2(9):870-5. PMID:11526404 doi:10.1038/ni0901-870
5. ↑ Jozic D, Cardenes N, Deribe YL, Moncalian G, Hoeller D, Groemping Y, Dikic I, Rittinger K, Bravo J. Cbl promotes clustering of endocytic adaptor proteins. Nat Struct Mol Biol. 2005 Nov;12(11):972-9. PMID:16228008 doi:http://dx.doi.org/10.1038/nsmb1000