Sequential and distinct roles of the cadherin domain-containing protein Axl2p in cell polarization in yeast cell cycle.
Polarization of cell growth along a defined axis is essential for the generation of cell and tissue polarity. In the budding yeast Saccharomyces cerevisiae, Axl2p plays an essential role in polarity-axis determination, or more specifically, axial budding in MATa or alpha cells. Axl2p is a type I membrane glycoprotein containing four cadherin-like motifs in its extracellular domain. However, it is not known when and how Axl2p functions together with other components of the axial landmark, such as Bud3p and Bud4p, to direct axial budding. Here, we show that the recruitment of Axl2p to the bud neck after S/G2 phase of the cell cycle depends on Bud3p and Bud4p. This recruitment is mediated via an interaction between Bud4p and the central region of the Axl2p cytoplasmic tail. This region of Axl2p, together with its N-terminal region and its transmembrane domain, is sufficient for axial budding. In addition, our work demonstrates a previously unappreciated role for Axl2p. Axl2p interacts with Cdc42p and other polarity-establishment proteins, and it regulates septin organization in late G1 independently of its role in polarity-axis determination. Together, these results suggest that Axl2p plays sequential and distinct roles in the regulation of cellular morphogenesis in yeast cell cycle.
Gao
Xiang-Dong
XD
Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6058, USA.
Sperber
Lauren M
LM
Kane
Steven A
SA
Tong
Zongtian
Z
Tong
Amy Hin Yan
AH
Boone
Charles
C
Bi
Erfei
E
D015820:Cadherins / Q000737:chemistry*; D002453:Cell Cycle; D016764:Cell Polarity; D016193:G1 Phase; D018628:Gene Dosage; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008954:Models, Biological; D050505:Mutant Proteins / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D013489:Suppression, Genetic
C098775:Axl2 protein, S cerevisiae; D015820:Cadherins; D008562:Membrane Glycoproteins; D050505:Mutant Proteins; D029701:Saccharomyces cerevisiae Proteins