Accumulation of plastocyanin mRNA lacking 5' region in the green alga Pediastrum boryanum grown under copper-deficient conditions.
In the green alga Pediastrum boryanum NIES-301, plastocyanin accumulates under copper-sufficient conditions and cytochrome c6 accumulates under copper-deficient conditions. We cloned the cDNA which encodes pre-apoplastocyanin from P. boryanum cultured under the copper-sufficient condition. The deduced amino acid sequence of the pre-apoplastocyanin protein consists of 151 amino acid residues including a putative bipartite presequence of 53 amino acid residues. Southern blot analysis of P. boryanum genomic DNA indicated that pre-apoplastocyanin is encoded by a single nuclear gene. Northern blot analysis showed that copper-deficient cells accumulated a shorter form of the mRNA of pre-apoplastocyanin, which did not generate pre-apoplastocyanin in the wheat-germ translation system. The difference in size was ascribed to the absence of the 5' region in the mRNA of pre-apoplastocyanin obtained from the copper-deficient cells, which accounts for the absence of plastocyanin under these conditions. This phenomenon represents a novel regulatory mechanism, although details of the mechanism are not yet known.
Nakamura
M
M
Department of Biology, Faculty of Science, Toho University, Funabashi, Chiba, Japan. mnakamur@med.toho-u.ac.jp
Yoshizaki
F
F
Sugimura
Y
Y
D020418:Algal Proteins / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D000460:Chlorophyta / Q000187:drug effects* / Q000235:genetics; D003300:Copper / Q000494:pharmacology*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005796:Genes / Q000235:genetics; D007438:Introns; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010970:Plastocyanin / Q000235:genetics* / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics; D012333:RNA, Messenger / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
D020418:Algal Proteins; D018076:DNA, Complementary; D011498:Protein Precursors; D012333:RNA, Messenger; D003300:Copper; D004247:DNA; D010970:Plastocyanin