The Saccharomyces cerevisiae RuvB-like protein, Tih2p, is required for cell cycle progression and RNA polymerase II-directed transcription.
Two highly conserved RuvB-like putative DNA helicases, p47/TIP49b and p50/TIP49a, have been identified in the eukaryotes. Here, we study the function of Saccharomyces cerevisiae TIH2, which corresponds to mammalian p47/TIP49b. Tih2p is required for vegetative cell growth and localizes in the nucleus. Immunoprecipitation analysis revealed that Tih2p tightly interacts with Tih1p, the counterpart of mammalian p50/TIP49a, which has been shown to interact with the TATA-binding protein and the RNA polymerase II holoenzyme complex. Furthermore, the mutational study of the Walker A motif, which is required for nucleotide binding and hydrolysis, showed that this motif plays indispensable roles in the function of Tih2p. When a temperature-sensitive tih2 mutant, tih2-160, was incubated at the nonpermissive temperature, cells were rapidly arrested in the G(1) phase. Northern blot analysis revealed that Tih2p is required for transcription of G(1) cyclin and of several ribosomal protein genes. The similarities between the mutant phenotypes of tih2-160 and those of taf145 mutants suggest a role for TIH2 in the regulation of RNA polymerase II-directed transcription.
Lim
C R
CR
Research and Education Center for Genetic Information and the Division of Gene Function in Animals, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara 630-0101, Japan.
Kimata
Y
Y
Ohdate
H
H
Kokubo
T
T
Kikuchi
N
N
Horigome
T
T
Kohno
K
K
D001426:Bacterial Proteins / Q000235:genetics; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics*; D004265:DNA Helicases; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D012319:RNA Polymerase II / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D005656:Fungal Proteins; C061260:RuvB protein, Bacteria; D012319:RNA Polymerase II; D004265:DNA Helicases