5hvj
From Proteopedia
Crystal structure of LIMK1 D460N mutant in complex with AMP-PNP
Structural highlights
DiseaseLIMK1_HUMAN Williams syndrome. Note=LIMK1 is located in the Williams-Beuren syndrome (WBS) critical region. WBS results from a hemizygous deletion of several genes on chromosome 7q11.23, thought to arise as a consequence of unequal crossing over between highly homologous low-copy repeat sequences flanking the deleted region. FunctionLIMK1_HUMAN Serine/threonine-protein kinase that plays an essential role in the regulation of actin filament dynamics. Acts downstream of several Rho family GTPase signal transduction pathways. Activated by upstream kinases including ROCK1, PAK1 and PAK4, which phosphorylate LIMK1 on a threonine residue located in its activation loop. LIMK1 subsequently phosphorylates and inactivates the actin binding/depolymerizing factors cofilin-1/CFL1, cofilin-2/CFL2 and destrin/DSTN, thereby preventing the cleavage of filamentous actin (F-actin), and stabilizing the actin cytoskeleton. In this way LIMK1 regulates several actin-dependent biological processes including cell motility, cell cycle progression, and differentiation. Phosphorylates TPPP on serine residues, thereby promoting microtubule disassembly. Stimulates axonal outgrowth and may be involved in brain development. Isoform 3 has a dominant negative effect on actin cytoskeletal changes.[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedCofilin/actin-depolymerizing factor (ADF) proteins are critical nodes that relay signals from protein kinase cascades to the actin cytoskeleton, in particular through site-specific phosphorylation at residue Ser3. This is important for regulation of the roles of cofilin in severing and stabilizing actin filaments. Consequently, cofilin/ADF Ser3 phosphorylation is tightly controlled as an almost exclusive substrate for LIM kinases. Here we determine the LIMK1:cofilin-1 co-crystal structure. We find an interface that is distinct from canonical kinase-substrate interactions. We validate this previously unobserved mechanism for high-fidelity kinase-substrate recognition by in vitro kinase assays, examination of cofilin phosphorylation in mammalian cells, and functional analysis in S. cerevisiae. The interface is conserved across all LIM kinases. Remarkably, we also observe both pre- and postphosphotransfer states in the same crystal lattice. This study therefore provides a molecular understanding of how kinase-substrate recognition acts as a gatekeeper to regulate actin cytoskeletal dynamics. Structural Basis for Noncanonical Substrate Recognition of Cofilin/ADF Proteins by LIM Kinases.,Hamill S, Lou HJ, Turk BE, Boggon TJ Mol Cell. 2016 May 5;62(3):397-408. doi: 10.1016/j.molcel.2016.04.001. PMID:27153537[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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