TY - JOUR

T1 - The Saccharomyces cerevisiae actin cytoskeletal component Bsp1p has an auxiliary role in actomyosin ring function and in the maintenance of bud-neck structure

AU - Wright, Daniel

AU - Munro, Ewen

AU - Corbett, Mark

AU - Bentley, Adam James

AU - Fullwood, Nigel J.

AU - Murray, Stephen

AU - Price, Clive

PY - 2008/4

Y1 - 2008/4

N2 - Iqg1p is a component of the actomyosin contractile ring that is required for actin recruitment and septum deposition. Cells lacking Iqg1p function have an altered bud-neck structure and fail to form a functional actomyosin contractile ring resulting in a block to cytokinesis and septation. Here it is demonstrated that increased expression of the actin cytoskeleton associated protein Bsp1p bypasses the requirement for contractile ring function. This also correlates with reduced bud-neck width and remedial septum formation. Increased expression of this protein in a temperature-sensitive iqg1-1 background causes remedial septum formation at the bud neck that is reliant upon chitin synthase III activity and restores cell separation. The observed suppression correlates with a restoration of normal bud-neck structure. While Bsp1p is a component of the contractile ring, its recruitment to the bud neck is not required for the observed suppression. Loss of Bsp1p causes a brief delay in the redistribution of the actin cytoskeleton normally observed at the end of actin ring contraction. Compromise of Iqg1p function, in the absence of Bsp1p function, leads to a profound change in the distribution of actin and the pattern of cell growth accompanied by a failure to complete cytokinesis and cell separation.

AB - Iqg1p is a component of the actomyosin contractile ring that is required for actin recruitment and septum deposition. Cells lacking Iqg1p function have an altered bud-neck structure and fail to form a functional actomyosin contractile ring resulting in a block to cytokinesis and septation. Here it is demonstrated that increased expression of the actin cytoskeleton associated protein Bsp1p bypasses the requirement for contractile ring function. This also correlates with reduced bud-neck width and remedial septum formation. Increased expression of this protein in a temperature-sensitive iqg1-1 background causes remedial septum formation at the bud neck that is reliant upon chitin synthase III activity and restores cell separation. The observed suppression correlates with a restoration of normal bud-neck structure. While Bsp1p is a component of the contractile ring, its recruitment to the bud neck is not required for the observed suppression. Loss of Bsp1p causes a brief delay in the redistribution of the actin cytoskeleton normally observed at the end of actin ring contraction. Compromise of Iqg1p function, in the absence of Bsp1p function, leads to a profound change in the distribution of actin and the pattern of cell growth accompanied by a failure to complete cytokinesis and cell separation.

KW - BUDDING YEAST

KW - POLARIZED GROWTH

KW - CELL-CYCLE

KW - WILD-TYPE

KW - PROTEIN

KW - CYTOKINESIS

KW - MYOSIN

KW - IQGAP

KW - SYNTHASE-3

KW - PATHWAY

UR - http://www.scopus.com/inward/record.url?scp=45849118013&partnerID=8YFLogxK

U2 - 10.1534/genetics.107.082685

DO - 10.1534/genetics.107.082685

M3 - Journal article

VL - 178

SP - 1903

EP - 1914

JO - Genetics

JF - Genetics

SN - 0016-6731

IS - 4

ER -