부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.febslet.2006.03.008 Byline: Jonathan M. Goldberg (a), Eric S. Wolpin (a), Leonard Bosgraaf (b), Bryan K. Clarkson (a), Peter J.M. Van Haastert (b), Janet L. Smith (a) Keywords: Dictyostelium; Chemotaxis; cGMP; Myosin; Regulatory light chain; Phosphorylation Abstract: Stimulation of Dictyostelium cells with the chemoattractant cAMP results in transient phosphorylation of the myosin regulatory light chain (RLC). We show that myosin light chain kinase A (MLCK-A) is responsible for RLC phosphorylation during chemotaxis, and that MLCK-A itself is transiently phosphorylated on threonine-166, dramatically increasing its catalytic activity. MLCK-A activation during chemotaxis is highly responsive to cellular cGMP levels and the cGMP-binding protein GbpC. MLCK-A.sup.- cells have a partial cytokinesis defect, and do not phosphorylate RLC in response to concanavalin A (conA), but cells lacking cGMP or GbpC divide normally and phosphorylate in response to conA. Thus MLCK-A is activated by a cGMP/GbpC-independent mechanism activated during cytokinesis or by conA, and a cGMP/GbpC-dependent pathway during chemotaxis. Author Affiliation: (a) Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472-2829, United States (b) Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands Article History: Received 7 November 2005; Revised 13 February 2006; Accepted 1 March 2006