H-4 HISTONE MESSENGER-RNA DECAY IN CELL-FREE-EXTRACTS INITIATES AT OR NEAR THE 3' TERMINUS AND PROCEEDS 3' TO 5'
H-4 HISTONE MESSENGER-RNA DECAY IN CELL-FREE-EXTRACTS INITIATES AT OR NEAR THE 3' TERMINUS AND PROCEEDS 3' TO 5'
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DOI：
10.1016/s0022-2836(86)80008-0
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发表时间：
1986-04-20
影响因子：
5.6
通讯作者：
KOBS, G
中科院分区：
文献类型：
--
作者：
ROSS, J;KOBS, G
在无细胞系统中比较了四种人类信使rna， γ珠蛋白，δ珠蛋白，c-myc和H4组蛋白的相对衰减。在适当的条件下，它们在体外的降解顺序与体内大致相同：组蛋白比c-myc快，δ珠蛋白比γ珠蛋白快。多体相关的H4组蛋白mRNA和去蛋白化组蛋白mRNA的降解开始于3'端或其附近。然后，至少一部分mRNA继续以3 “到5 ”的方向降解。观察到离散的3”端退化保持点，表明3”到5”退化发生不均匀。环己亚胺和嘌呤霉素抑制蛋白合成，但不影响组蛋白mRNA在体外降解的速率和方向性。我们得出结论，H4组蛋白mRNA衰变的限速步骤发生在3”末端或附近，并且mRNA分子的至少一部分随后被降解3”到5”，可能是通过过程外切酶。
The relative decay of four human messenger RNAs, gamma globin, delta globin, c-myc and H4 histone, were compared in a cell-free system. Under appropriate conditions, they are degraded in vitro in approximately the same relative order as in vivo: histone faster than c-myc and delta globin faster than gamma globin. Degradation of polysome-associated H4 histone mRNA and of deproteinized histone mRNA begins at or near the 3'' terminus. At least a portion of the mRNA then continues to be degraded in a 3'' to 5'' direction. Discrete 3''-terminal degradation hold-up points are observed, suggesting that 3'' to 5'' degradation occurs non-uniformly. Cycloheximide and puromycin inhibit protein synthesis but do not affect the rate or directionality of histone mRNA decay in vitro. We conclude that the rate-limiting step in H4 histone mRNA decay occurs at or near the 3'' terminus and that at least a portion of the mRNA molecule is subsequently degraded 3'' to 5'', probably via processive exonuclease.