%0 Journal Article
%T Crosstalk between NDR kinase pathways coordinates cell cycle dependent actin rearrangements
%A Sneha Gupta
%A Dannel McCollum
%J Cell Division
%D 2011
%I BioMed Central
%R 10.1186/1747-1028-6-19
%X Schizosaccharomyces pombe are rod-shaped cells that grow by elongation at cell ends and divide by medial fission. These cells form an ideal system for the study of biochemical signaling pathways that underlie cell polarity and morphogenesis. The NDR kinase signaling cascades that control various aspects of growth and division in fission yeast are conserved in higher eukaryotes where they retain similar functions but have also acquired new ones (Figure 1) [1,2].The Morphogenesis Orb6 Network (MOR), one of the two conserved NDR kinase pathways in fission yeast, is active throughout interphase and controls cell morphology and tip growth through accretion of actin to sites of cell growth [3,4]. Actin is required at the cell tips for formation of F-actin patch structures as well as actin cables. While actin patches are well established as sites of active cell growth, actin cables serve as tracks on which a variety of cargo for cell growth and polarity are delivered to the cell ends [5-7]. The MOR has been implicated in F-actin patch assembly [8]. Moreover, it also regulates localization of the F-actin cable polymerization factor, For3 at the cell tips via spatial control of the Cdc42 GTPase, a central regulator of cell polarity [9]. The MOR signaling pathway includes Orb6 (an NDR kinase) [3]; its binding partner Mob2 [10] and its upstream activator, Nak1 (a STE-20 like kinase) [11,12]. Pmo25 has been identified as a binding partner of Nak1 and is essential for the activities of both kinases in the pathway [4]. Mor2, which is a homolog of the Drosophila Furry protein, is thought to act as a scaffold that promotes the activation of Orb6 by Nak1 [13]. Mutants in any of the MOR components fail to grow in a polarized manner resulting in round morphology of the cells.The Septation Initiation Network (SIN) constitutes the other NDR kinase pathway in fission yeast and is activated during late mitosis where it plays an essential role in cytokinesis. The SIN signaling cascade is r
%K SIN
%K MOR
%K polarity
%K cytokinesis
%K actin cytoskeleton
%U http://www.celldiv.com/content/6/1/19