Cloning and characterization of two yeast genes encoding members of the CCCH class of zinc finger proteins: zinc finger-mediated impairment of cell growth.
Members of the CCCH zinc finger (Zf) protein family have in common two or more repeats of a novel Zf motif consisting of Cys and His residues in the form Cx8Cx5Cx3H [where x is a variable amino acid (aa)]. We used a degenerate polymerase chain reaction (PCR) strategy to clone members of this gene family from Saccharomyces cerevisiae. The deduced aa sequences encoded by these genes, designated CTH1 and CTH2, share 46% overall identity and 59% similarity, largely due to the two highly conserved Zf domains. We found readily detectable expression of a 1.4-kb mRNA encoding Cth1p. The 1.1-kb mRNA encoding Cth2p was barely detectable under normal growth conditions; however, disruption of CTH1 resulted in at least a threefold increase in CTH2 mRNA accumulation. No change in phenotype was detected following disruption of CTH1 and CTH2, either singly or together. In contrast, overexpression of the CTH genes or one of the related mammalian genes, tris-tetraprolin (TTP), caused delayed entry of cell cultures into exponential growth, and a decrease in final cell density. Removal of the Zf domain of Cth1p by truncation or deletion completely reversed this slow growth phenotype, indicating that it was mediated through this highly conserved structural motif.
Howard Hughes Medical Institute Laboratories, Duke University Medical Center, Durham, NC 27710, USA.
M J
MJ
Thompson
W S
WS
Lai
G A
GA
Taylor
P J
PJ
Blackshear
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D006133:Growth Substances / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics*; D051816:Tristetraprolin; D016335:Zinc Fingers / Q000235:genetics
C102098:CTH1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D006133:Growth Substances; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C091790:TIS11 protein, S cerevisiae; D014157:Transcription Factors; D051816:Tristetraprolin