A cdc5+ homolog of a higher plant, Arabidopsis thaliana

A cdc5⁺ homolog of a higher plant, Arabidopsis thaliana

Takashi Hirayama* and
Kazuo Shinozaki*,†

^*Laboratory of Plant Molecular Biology, Tsukuba Life Science Center, The Institute of Physical and Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305, Japan

Abstract

We cloned and characterized a cDNA corresponding to a cdc5 ⁺ homolog of the higher plant, Arabidopsis thaliana. The cDNA, named AtCDC5 cDNA, encodes a polypeptide of 844 amino acid residues. The amino acid sequence of N-terminal one-fourth region of the predicted protein bears significant similarity to that of Schizosaccharomyces pombe Cdc5 and Myb-related proteins. Overexpression of the AtCDC5 cDNA in S. pombe cells is able to complement the growth defective phenotype of a cdc5 temperature-sensitive mutant. These results indicate that the AtCDC5 gene is a plant counterpart of S. pombe cdc5 ⁺. This is the first report of a cdc5 ⁺-like gene in a multicellular organism. We also demonstrated that a recombinant AtCDC5 protein possesses a sequence specific DNA binding activity (CTCAGCG) and the AtCDC5 gene is expressed extensively in shoot and root meristems. In addition, we cloned a PCR fragment corresponding to the DNA binding domain of human Cdc5-like protein. These results strongly suggest that Cdc5-like protein exists in all eukaryotes and may function in cell cycle regulation.

Footnotes

↵ † To whom reprint requests should be addressed.
Jozef Schell, Max-Planck-Institut für Züchtungsforschung, Cologne, Germany
Abbreviation: GST; glutathione S-transferase.

Data deposition: The sequences reported in this paper have been deposited in the GenBank data base (accession nos. D58424D58424 and D85423D85423 for AtCDC5 and human Cdc5, respectively).