[Synthesis of specific RNA at the early S-stage of the cell cycle of the myxomycete Physarum polycephalum].
Incorporation of [3H]uridine into polyribosomes and polyribosomal RNA at different stages of the cell cycle of myxomycete Physarum polycephalum was investigated. It has been shown that at the early S-stage (during the first hour after mitosis) there is no rRNA synthesis. About 10--12% of polyribosomal RNA, synthesized during this period is poly(A)+RNA. Approximately 50% of poly(A)-RNA sediments as 4--6S and 20--25% as 7--14S in sucrose density gradient. It has been found that labeled RNA is associated with the light polyribosome fractions. The bulk of RNA synthesized during other periods of the cell cycle consists of rRNA, which is evenly distributed between different polysome fractions. We suppose that light polyribosomes are involved in the protein synthesis at the early S-stage of the cell cycle. 4--6S and 7--14S polyribosomal poly(A)-RNA was investigated by electrophoresis in denaturing conditions. By comparing with other organisms we may suppose that the 7--14S poly(A)-RNA, synthesized during the beginning of the S-stage is histone messenger RNA.
D002453:Cell Cycle; D007399:Interphase; D007700:Kinetics; D010804:Physarum / Q000502:physiology*; D011132:Polyribosomes / Q000378:metabolism; D012331:RNA, Fungal / Q000096:biosynthesis*; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D014529:Uridine / Q000378:metabolism
D012331:RNA, Fungal; D012335:RNA, Ribosomal; D014529:Uridine
Sintez spetsificheskikh RNK na ranneĭ S-stadii kletochnogo tsikla miksomitseta Physarum polycephalum.