The yeast TEM1 gene, which encodes a GTP-binding protein, is involved in termination of M phase.
LTE1 belongs to the CDC25 family that encodes a guanine nucleotide exchange factor for GTP-binding proteins of the ras family. Previously we have shown that LTE1 is essential for termination of M phase at low temperatures. We have identified TEM1 as a gene that, when present on a multicopy plasmid, suppresses the cold-sensitive phenotype of lte1. Sequence analysis of TEM1 and GTP-binding analysis of the gene product revealed that TEM1 encodes a novel low-molecular-weight GTP-binding protein. The defect of TEM1 was lethal, and the tem1-defective cells were arrested at telophase with high H1-kinase activity under restrictive conditions, indicating that TEM1 is required to exit from M phase. The defect of TEM1 was suppressed by a high dose of CDC15, which encodes a protein kinase homologous to mitogen-activated protein kinase kinase kinases. The genetic interaction among LTE1, TEM1, and CDC15 indicates that they cooperatively play an essential role for termination of M phase.
Shirayama
M
M
Department of Biology, University of Tokyo, Japan.
Matsui
Y
Y
Toh-E
A
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005800:Genes, Fungal; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D006656:Protamine Kinase / Q000378:metabolism; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins
D004271:DNA, Fungal; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C089965:TEM1 protein, S cerevisiae; D006656:Protamine Kinase; D019204:GTP-Binding Proteins; D020559:Monomeric GTP-Binding Proteins