The thylakoid membranes of cyanobacteria form a complex intracellular membrane system with a distinctive proteome. The sites of biogenesis of thylakoid proteins remain uncertain, as do the signals that direct thylakoid membrane-integral proteins to the thylakoids rather than to the plasma membrane. Here, we address these questions by using fluorescence in situ hybridization to probe the subcellular location of messenger RNA molecules encoding core subunits of the photosystems in two cyanobacterial species. These mRNAs cluster at thylakoid surfaces mainly adjacent to the central cytoplasm and the nucleoid, in contrast to mRNAs encoding proteins with other locations. Ribosome association influences the distribution of the photosynthetic mRNAs on the thylakoid surface, but thylakoid affinity is retained in the absence of ribosome association. However, thylakoid association is disrupted in a mutant lacking two mRNA-binding proteins, which probably play roles in targeting photosynthetic proteins to the thylakoid membrane.

蓝细菌的类囊体膜形成具有独特蛋白质组的复杂细胞内膜系统。类囊体蛋白的生物发生部位仍然不确定，将类囊体膜整合蛋白导向类囊体而不是质膜的信号也不确定。在这里，我们通过使用荧光原位杂交来探究编码两个蓝细菌物种中光系统核心亚基的信使RNA分子的亚细胞位置，从而解决了这些问题。与编码具有其他位置的蛋白质的mRNA相比，这些mRNA聚集在类囊体表面，主要邻近中央细胞质和核苷酸。核糖体缔合影响光合mRNA在类囊体表面的分布，但是在没有核糖体缔合的情况下，类囊体亲和力得以保留。然而，