Yeast Genetics and Molecular Biology 1996
Madison, Wisconsin
August 1996


Name: Caro, Louise H
Mailing Address: Kruislaan 318, Amsterdam, NL 1098SM The Netherlands
Email Address: caro@bio.uva.nl
Phone and Fax numbers: +31 20 525 7841, +31 20 525 7934

Cell cycle regulated expression of cell wall protein encoding genes in Saccharomyces cerevisiae.

L.H.P. Caro1, P. van Egmond1, J.W. Chapman2 and F.M. Klis1. 1) BioCentrum Amsterdam, Institute for Molecular Cell Biology, University of Amsterdam, Kruislaan 318, 1098 SM Amsterdam, The Netherlands; (+31) 20 525 7841; 2) Unilever Research Laboratory, The Netherlands.

Cell wall synthesis and assembly are under strict cellular control both in space and in time. Transcript levels of CHS3, encoding chitin synthase III, varied during the cell cycle and reached a maximum late in the cell cycle after a septum had been formed [1]. FKS1, encoding a component of the *beta*1,3-glucan synthesizing complex showed a cell cycle regulated expression, mRNA levels peaking at the G1/S-transition [2]. Here we show that the expression of glucosylated manno-proteins, is regulated during the cell cycle. In *alpha*-pheromone synchronized cells, levels of CWP1 mRNA peaked during the S-phase to levels six times higher than those during the G1-phase. mRNA levels of CWP2 peaked at the same time as CWP1-mRNAs, but to a lesser extend. Other cell wall protein encoding genes, like TIP1, did not show this cell cycle regulated expression. Taken together, to form the new daughter cell, first the synthesis of glucan is induced, next that of manno-proteins and finally that of chitin. Therefore genes involved in the synthesis of every component of the cell wall studied so far, are under control of the cell cycle machinery, indicating that cell wall synthesis and assembly are strictly regulated during the cell cycle. 1. Pammer et al. (1992) Yeast 8, 1089-1099. 2. Ram et al. (1995) FEBS Lett. 358, 165-170.