Smith S M, Ellis R J
J Mol Appl Genet. 1981;1(2):127-37.
The chloroplast enzyme, ribulosebisphosphate carboxylase, consists of large subunit polypeptides encoded in the chloroplast genome and small subunit polypeptides encoded in the nuclear genome. Cloned DNA complementary to the small subunit mRNA hybridizes to a single RNA species of 900-1000 nucleotides in both total and poly(A)-containing RNA from leaves of Pisum sativum, but does not hybridize to chloroplast RNA. Small subunit cDNA hybridizes to at least three RNA species from nuclei, two of which are of higher molecular weight than the mature mRNA. A cloned large subunit DNA sequence hybridizes to a single species of Pisum chloroplast RNA containing approximately 1700 nucleotides, but does not hybridize to nuclear RNA. The light-stimulation of carboxylase accumulation reflects increases in the amounts of transcripts for both subunits in total leaf RNA. Transcripts of the small subunit gene are more abundant in nuclear RNA from light-grown leaves than in that from dark-grown leaves. These results suggest that the stimulation of carboxylase accumulation by light is mediated at the level of either transcription or RNA turnover in both nucleus and chloroplast.
叶绿体酶核酮糖二磷酸羧化酶由叶绿体基因组编码的大亚基多肽和核基因组编码的小亚基多肽组成。与小亚基mRNA互补的克隆DNA，在来自豌豆叶片的总RNA和含poly(A)的RNA中，均与一种900 - 1000个核苷酸的单一RNA种类杂交，但不与叶绿体RNA杂交。小亚基cDNA与来自细胞核的至少三种RNA种类杂交，其中两种的分子量高于成熟mRNA。一个克隆的大亚基DNA序列与一种约含1700个核苷酸的豌豆叶绿体RNA单一种类杂交，但不与核RNA杂交。羧化酶积累的光刺激反映了总叶片RNA中两个亚基转录本数量的增加。小亚基基因的转录本在光下生长叶片的核RNA中比在暗中生长叶片的核RNA中更丰富。这些结果表明，光对羧化酶积累的刺激是在细胞核和叶绿体中的转录或RNA周转水平上介导的。
