Cell shape regulation by Gravin requires N-terminal membrane effector domains.
Gravin (AKAP12, SSeCKS) is a scaffolding protein that acts as a potent inhibitor of tumor metastasis in vivo and in vitro, and regulates morphogenesis during vertebrate gastrulation. Despite being implicated in many cellular processes, surprisingly little is known about the mechanism by which Gravin elicits cell shape changes. In this work, we use in vitro cell spreading assays to demonstrate that the Gravin N-terminus containing the three MARCKS-like basic regions (BRs) is necessary and sufficient to regulate cell shape in vitro. We show that the conserved phosphorylation sites in the BRs are essential for their function in these assays. We further demonstrate that the Gravin BRs are necessary for in vivo function during gastrulation in zebrafish. Together, these results provide an important step forward in understanding the mechanism of Gravin function in cell shape regulation and provide valuable insight into how Gravin acts as a cytoskeletal regulator.
Weiser
Douglas C
DC
Department of Biochemistry, University of Washington, Seattle WA 98195.
St Julien
Krystal R
KR
Department of Biochemistry, University of Washington, Seattle WA 98195.
Lang
James S
JS
Department of Biochemistry, University of Washington, Seattle WA 98195.
Kimelman
David
D
Department of Biochemistry, University of Washington, Seattle WA 98195.
D054758:A Kinase Anchor Proteins / Q000235:genetics / Q000502:physiology*; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000201:enzymology; D002465:Cell Movement / Q000235:genetics; D048430:Cell Shape / Q000235:genetics; D002522:Chlorocebus aethiops; D017434:Protein Structure, Tertiary; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics / Q000502:physiology*
D054758:A Kinase Anchor Proteins; D029961:Zebrafish Proteins; C532501:akap12b protein, zebrafish