Winder T L, Anderson J C, Spalding M H
Department of Botany, Iowa State University, Ames, Iowa 50010.
Plant Physiol. 1992 Apr;98(4):1409-14. doi: 10.1104/pp.98.4.1409.
In conditions of limiting external inorganic carbon, the unicellular alga Chlamydomonas reinhardtii induces a mechanism to actively transport and accumulate inorganic carbon within the cell. A high internal inorganic carbon concentration enables the cell to photosynthesize efficiently with little oxygen inhibition, even in conditions of limiting external inorganic carbon. A correlation between limiting inorganic carbon-induced induction of the CO(2)-concentrating mechanism and decreased synthesis of the large and small subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase has been observed. Cells that had been transferred from elevated CO(2) to limiting CO(2) exhibit transient declines of label incorporation into both subunit polypeptides. We have found that this decrease in synthesis of large and small subunits results from specific and coordinated down-regulation of translation of both subunits possibly resulting, at least in part, from modification of large and small subunit transcripts.
在外部无机碳受限的条件下，单细胞藻类莱茵衣藻会诱导一种机制，以便在细胞内主动运输和积累无机碳。即使在外部无机碳受限的条件下，较高的细胞内无机碳浓度也能使细胞在几乎没有氧气抑制的情况下高效地进行光合作用。已经观察到无机碳限制诱导的二氧化碳浓缩机制与1,5-二磷酸核酮糖羧化酶/加氧酶大亚基和小亚基合成减少之间存在相关性。从高浓度二氧化碳环境转移到低浓度二氧化碳环境的细胞，其两种亚基多肽的标记掺入量会出现短暂下降。我们发现，大亚基和小亚基合成的减少是由于这两种亚基翻译的特异性和协调性下调所致，这可能至少部分是由大亚基和小亚基转录本的修饰引起的。
