The phosphoglycolate phosphatase gene and the mutation in the phosphoglycolate phosphatase-deficient mutant (pgp1-1) of Chlamydomonas reinhardtii

Authors

Kensaku Suzuki, National Agricultural Research Center for Tohoku Region, Morioka, JapanFollow
Hidenobu Uchida, National Agricultural Research Center for Tohoku Region, Morioka, Japan
Tarlan G. Mamedov, University of Nebraska-LincolnFollow

Date of this Version

7-2005

Comments

Published in Canadian Journal of Botany 83: 842–849 (2005); copyright © 2005 NRC Canada. Used by permission.

Abstract

The sequences of the phosphoglycolate phosphatase (PGPase) gene Pgp1 and the 5′-upstream region from Chlamydomonas reinhardtii wildtype 2137 and the pgp1-1 mutant N142 that lacks the activity of PGPase (PGP1) were determined. The comparison revealed the alteration of a G to A at position 98 relative to the start codon. This destroyed the “GT” splice donor site at the beginning of the first intron of this gene, resulting in an extension of the first exon to 49 translatable codons followed by a stop codon, containing the codons corresponding to whole transit peptide for the chloroplast stroma and the first four N-terminal amino-acid residues of the PGP1 subunit. The comparison of the upstream nucleotide sequence of Pgp1 with those of 37 other genes including those involved in the CO₂-concentrating mechanism and (or) photorespiration showed the high similarity of Pgp1 upstream to a periplasmic carbonic anhydrase gene Cah1; the motifs RAGGTCAGN_8–9CCR and TTGGCAG were found only within the low-CO₂ responsive genes, including Pgp1 and Cah1. GAN₇CGNTTGGAAN₂AG, TTGGAAGGAG, and CAGAGGTCAGN₈CCG were found only with Pgp1 and Cah1, and ACGCTTGGCAGT and CATTACCAT were found only with Pgp1 and alanine aminotransferase gene Aat1. The possibility of functional PGPase isozyme(s) in C. reinhardtii is also discussed.