3lk3
Crystal structure of CapZ bound to the CPI and CSI uncapping motifs from CARMILCrystal structure of CapZ bound to the CPI and CSI uncapping motifs from CARMIL
Structural highlights
Function[CAZA1_CHICK] F-actin-capping proteins bind in a Ca(2+)-independent manner to the fast growing ends of actin filaments (barbed end) thereby blocking the exchange of subunits at these ends. Unlike other capping proteins (such as gelsolin and severin), these proteins do not sever actin filaments. CapZ may mediate the attachment of the barbed ends of actin filaments to the Z-line. [LR16A_HUMAN] Binds CAPZA2 with high affinity and significantly decreases CAPZA2 affinity for actin barbed ends. Increases the rate of elongation from seeds in the presence of CAPZA2, however, seems unable to nucleate filaments. Rapidly uncaps barbed ends capped by CAPZA2 and enhances barbed-end actin polymerization (By similarity).[1] [CAPZB_CHICK] F-actin-capping proteins bind in a Ca(2+)-independent manner to the fast growing ends of actin filaments (barbed end) thereby blocking the exchange of subunits at these ends. Unlike other capping proteins (such as gelsolin and severin), these proteins do not sever actin filaments. May play a role in the regulation of cell morphology and cytoskeletal organization. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCapping protein (CP) regulates actin dynamics by binding the barbed ends of actin filaments. Removal of CP may be one means to harness actin polymerization for processes such as cell movement and endocytosis. Here we structurally and biochemically investigated a CP interaction (CPI) motif present in the otherwise unrelated proteins CARMIL and CD2AP. The CPI motif wraps around the stalk of the mushroom-shaped CP at a site distant from the actin-binding interface, which lies on the top of the mushroom cap. We propose that the CPI motif may act as an allosteric modulator, restricting CP to a low-affinity, filament-binding conformation. Structure-based sequence alignments extend the CPI motif-containing family to include CIN85, CKIP-1, CapZIP and a relatively uncharacterized protein, WASHCAP (FAM21). Peptides comprising these CPI motifs are able to inhibit CP and to uncap CP-bound actin filaments. Structural characterization of a capping protein interaction motif defines a family of actin filament regulators.,Hernandez-Valladares M, Kim T, Kannan B, Tung A, Aguda AH, Larsson M, Cooper JA, Robinson RC Nat Struct Mol Biol. 2010 Apr;17(4):497-503. Epub 2010 Mar 28. PMID:20357771[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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