Dephosphorylation of serine 3 regulates nuclear translocation of cofilin.
Signal transduction processes in T-cells and other cell types alter the phosphorylation state of cofilin, an actin-binding phosphoprotein. Whether reversible phosphorylation is responsible for the regulation of the functional activities of cofilin is not clear at present. Here we have identified the phosphoacceptor site of cofilin and analyzed the role of cofilin phosphorylation with respect to its subcellular localization. Site-directed mutagenesis studies show that phosphorylation occurs exclusively on Ser-3. Expression of non-phosphorylatable mutant cofilin proteins in NIH3T3 cells and determination of their subcellular localization by confocal laser scanning microscopy reveal that non-phosphorylated cofilin accumulates within nuclei. This analysis shows that the subcellular localization of cofilin depends on the phosphorylation state of Ser-3.
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Institute for Immunology, Ruprecht-Karls-University, Im Neuenheimer Feld 305, 69120 Heidelberg, Federal Republic of Germany.
Meuer
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SC
Samstag
Y
Y
D016475:3T3 Cells; D051339:Actin Depolymerizing Factors; D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002460:Cell Line; D000939:Epitopes; D005260:Female; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D008840:Microfilament Proteins; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009842:Oligopeptides; D010455:Peptides / Q000378:metabolism; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012694:Serine / Q000378:metabolism*; D013329:Structure-Activity Relationship
D051339:Actin Depolymerizing Factors; D000939:Epitopes; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009842:Oligopeptides; D010455:Peptides; D011993:Recombinant Fusion Proteins; D012694:Serine; C085706:FLAG peptide