Genetics, Vol 147, 1595-1607, Copyright © 1997


INVESTIGATIONS

Mutations Synthetically Lethal With tpm1{delta} Lie in Genes Involved in Morphogenesis

T. Wang and A. Bretscher
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853

Yeast contains two genes, TPM1 and TPM2, encoding tropomyosins, either of which can provide an essential function in the yeast cytoskeleton. To elucidate more clearly the function of the major tropomyosin, encoded by TPM1, we have isolated mutations that confer synthetic lethality with the null mutant of TPM1. Here we describe a phenotypic and genetic analysis of mutations in TSL1/BEM2, TSL2, TSL3, TSL5, and TSL6 (tropomyosin synthetic lethal). All the mutants exhibit clear morphological and some actin cytoskeletal defects, but are not noticeably defective in secretion, endocytosis, or organelle segregation. The lethality conferred by tsl tpm1{delta} mutations could be specifically suppressed by either TPM1 or an additional copy of TPM2. This implies that the essential function compromised in the tsl tpm1{delta} constructs is the same essential function for which Tpm1p or Tpm2p is necessary. Synthetic interactions and unlinked noncomplementation were observed between the tsl mutants, suggesting that they participate in related functions involving morphogenesis. In support of this, tsl6-1 was identified as an allele of the nonessential gene SLT2 or MPK1 whose product is a MAP kinase regulating cell wall synthesis. These results indicate that this synthetic lethality approach provides a sensitive screen for the isolation of mutations affecting morphogenesis, many of which are likely to be in nonessential genes, like BEM2 and SLT2.


This article has been cited by other articles:


Home page
ScienceHome page
A. H. Y. Tong, M. Evangelista, A. B. Parsons, H. Xu, G. D. Bader, N. Page, M. Robinson, S. Raghibizadeh, C. W. V. Hogue, H. Bussey, et al.
Systematic Genetic Analysis with Ordered Arrays of Yeast Deletion Mutants
Science, December 14, 2001; 294(5550): 2364 - 2368.
[Abstract] [Full Text] [PDF]


Home page
Mol. Biol. CellHome page
J. Ho and A. Bretscher
Ras Regulates the Polarity of the Yeast Actin Cytoskeleton through the Stress Response Pathway
Mol. Biol. Cell, June 1, 2001; 12(6): 1541 - 1555.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
K. J. Yook, S. R. Proulx, and E. M. Jorgensen
Rules of Nonallelic Noncomplementation at the Synapse in Caenorhabditis elegans
Genetics, May 1, 2001; 158(1): 209 - 220.
[Abstract] [Full Text]


Home page
Mol. Biol. CellHome page
R. A. Heil-Chapdelaine, N. K. Tran, and J. A. Cooper
Dynein-dependent Movements of the Mitotic Spindle in Saccharomyces cerevisiae Do Not Require Filamentous Actin
Mol. Biol. Cell, March 1, 2000; 11(3): 863 - 872.
[Abstract] [Full Text]


Home page
J. Cell Sci.Home page
D Pruyne and A Bretscher
Polarization of cell growth in yeast
J. Cell Sci., January 2, 2000; 113(4): 571 - 585.
[Abstract] [PDF]