Structural highlights
Function
CALM1_RAT Calmodulin mediates the control of a large number of enzymes, ion channels, aquaporins and other proteins through calcium-binding. Among the enzymes to be stimulated by the calmodulin-calcium complex are a number of protein kinases and phosphatases. Together with CCP110 and centrin, is involved in a genetic pathway that regulates the centrosome cycle and progression through cytokinesis. Mediates calcium-dependent inactivation of CACNA1C. Positively regulates calcium-activated potassium channel activity of KCNN2.[UniProtKB:P62158]
Publication Abstract from PubMed
RalA is a small GTPase and a member of the Ras family. This molecular switch is activated downstream of Ras and is widely implicated in tumor formation and growth. Previous work has shown that the ubiquitous Ca(2+)-sensor calmodulin (CaM) binds to small GTPases such as RalA and K-Ras4B, but a lack of structural information has obscured the functional consequences of these interactions. Here, we have investigated the binding of CaM to RalA and found that CaM interacts exclusively with the C terminus of RalA, which is lipidated with a prenyl group in vivo to aid membrane attachment. Biophysical and structural analyses show that the two RalA membrane-targeting motifs (the prenyl anchor and the polybasic motif) are engaged by distinct lobes of CaM and that CaM binding leads to removal of RalA from its membrane environment. The structure of this complex, along with a biophysical investigation into membrane removal, provides a framework with which to understand how CaM regulates the function of RalA and sheds light on the interaction of CaM with other small GTPases, including K-Ras4B.
Calmodulin extracts the Ras family protein RalA from lipid bilayers by engagement with two membrane-targeting motifs.,Chamberlain SG, Gohlke A, Shafiq A, Squires IJ, Owen D, Mott HR Proc Natl Acad Sci U S A. 2021 Sep 7;118(36):e2104219118. doi: , 10.1073/pnas.2104219118. PMID:34480001[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Chamberlain SG, Gohlke A, Shafiq A, Squires IJ, Owen D, Mott HR. Calmodulin extracts the Ras family protein RalA from lipid bilayers by engagement with two membrane-targeting motifs. Proc Natl Acad Sci U S A. 2021 Sep 7;118(36):e2104219118. PMID:34480001 doi:10.1073/pnas.2104219118
