4xc2
From Proteopedia
Crystal structure of GABARAP in complex with KBTBD6 LIR peptide
Structural highlights
FunctionGBRAP_HUMAN May play a role in intracellular transport of GABA(A) receptors and its interaction with the cytoskeleton. Involved in apoptosis. Involved in autophagy (By similarity).[1] Publication Abstract from PubMedThe small Rho GTPase RAC1 is an essential regulator of cellular signaling that controls actin rearrangements and cell motility. Here, we identify a novel CUL3 RING ubiquitin ligase complex, containing the substrate adaptors KBTBD6 and KBTBD7, that mediates ubiquitylation and proteasomal degradation of TIAM1, a RAC1-specific GEF. Increasing the abundance of TIAM1 by depletion of KBTBD6 and/or KBTBD7 leads to elevated RAC1 activity, changes in actin morphology, loss of focal adhesions, reduced proliferation, and enhanced invasion. KBTBD6 and KBTBD7 employ ATG8 family-interacting motifs to bind preferentially to GABARAP proteins. Surprisingly, ubiquitylation and degradation of TIAM1 by CUL3KBTBD6/KBTBD7 depends on its binding to GABARAP proteins. Our study reveals that recruitment of CUL3KBTBD6/KBTBD7 to GABARAP-containing vesicles regulates the abundance of membrane-associated TIAM1 and subsequently spatially restricted RAC1 signaling. Besides their role in autophagy and trafficking, we uncovered a previously unknown function of GABARAP proteins as membrane-localized signaling scaffolds. CUL3-KBTBD6/KBTBD7 Ubiquitin Ligase Cooperates with GABARAP Proteins to Spatially Restrict TIAM1-RAC1 Signaling.,Genau HM, Huber J, Baschieri F, Akutsu M, Dotsch V, Farhan H, Rogov V, Behrends C Mol Cell. 2015 Feb 11. pii: S1097-2765(14)01018-1. doi:, 10.1016/j.molcel.2014.12.040. PMID:25684205[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Homo sapiens | Large Structures | Akutsu M | Baschieri F | Behrends C | Doetsch V | Farhan H | Genau HM | Huber J | Rogov VV