A Myosin Light Chain Mediates the Localization of the Budding Yeast IQGAP-Like Protein during Contractile Ring Formation
Cytokinesis in animal cells is accomplished through constriction of an actomyosin ring, which must assemble at the correct time and place in order to ensure proper division of genetic material and organelles. Budding yeast is a useful model system for determining the biochemical pathway of contractile ring assembly. The budding yeast IQGAP-like protein, Cyk1/Iqg1p, has multiple roles in the assembly and contraction of the actomyosin ring. Previously, the IQ motifs of Cyk1/Iqg1p were shown to be required for the localization of this protein at the bud neck. We have investigated the binding partner of the IQ motifs, which are predicted to interact with calmodulin-like proteins. Mlc1p was originally identified as a light chain for a type V myosin, Myo2p; however, a cytokinesis defect associated with disruption of the MLC1 gene suggested that the essential function of Mlc1p may involve interactions with other proteins. We show that Mlc1p binds the IQ motifs of Cyk1/Iqg1p and present evidence that this interaction recruits Cyk1/Iqg1p to the bud neck. Immunofluorescence staining shows that Mlc1p is localized to sites of polarized cell growth as well as the bud neck before and independently of Cyk1p. These results demonstrate that Mlc1p is important for the assembly of the actomyosin ring in budding yeast and that this function is mediated through interaction with Cyk1/Iqg1p.
K. Shannon and R. Li, "A Myosin Light Chain Mediates the Localization of the Budding Yeast IQGAP-Like Protein during Contractile Ring Formation," Current Biology, vol. 10, no. 12, pp. 727-730, Cell Press, Jan 2000.
The definitive version is available at http://dx.doi.org/10.1016/S0960-9822(00)00539-X
Keywords and Phrases
Actin Binding Protein; Fungal Protein; Guanosine Triphosphatase Activating Protein; IQ Motif Containing Guanosine Triphosphatase Activating Protein 1; Myosin Light Chain; Article; Growth, Development and Aging; Metabolism; Saccharomyces Cerevisiae; Fungal Proteins; Microfilament Proteins; Myosin Light Chains; Ras GTPase-Activating Proteins; Saccharomyces Cerevisiae
International Standard Serial Number (ISSN)
Article - Journal
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