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Regulation of protein synthesis in mitotic HeLa cells
Author(s) -
Tarnowka Miroslaw A.,
Baglioni Corrado
Publication year - 1979
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040990311
Subject(s) - protein biosynthesis , ribosome , hela , mitosis , in vitro , messenger rna , biology , rna , ribosomal rna , microbiology and biotechnology , biochemistry , gene
Mitotic HeLa cells (M cells) synthesize protein at about 25% of the rate of S phase cells. This decrease in protein synthesis is due to a reduction in the rate of initiation. However, extracts prepared from M cells are almost as active in protein synthesis as S cell extracts. Both cell extracts are quite active in in vitro initiation of protein synthesis. Moreover, two steps in initiation, binding of Met‐tRNA f to 40S ribosomal subunits and binding of mRNA to ribosomes, show similar activity in both extracts. The difference in protein synthesizing activity observed in vivo is largely eliminated in the preparation of cell‐free systems. The ribosomes of M cells contain small mot wt RNA, which inhibits protein synthesis in vitro. This RNA, which has possibly a nuclear origin, may be a cause of the reduction in the rate of protein synthesis in M cells.