Isolation and characterization of nuclear particles containing rapidly labelled hnRNA and snRNA in combination with a distinct set of polypeptides of Mr 74000 and 72000.
A heterogeneous RNP structure has been isolated from rat liver nuclei by a method previously used for the isolation of 30S RNP complexes carrying heterogeneous RNA (hnRNA) [1]. The RNP sediments in sucrose gradients with s-values of 70-110S. Formaldehyde-fixed preparations band at Q = 1.40 in isopycnic CsCl gradients. The RNP structure is composed of a heterogeneous population of polypeptides, prominent among which are two proteins with Mr 74000 and 72000. It contains both rapidly labelled RNA as well as several species of snRNA, as demonstrated by double-labelling experiments and gel electrophoresis. Treatment of rats with alpha-amanitin leads to a significant decrease in the amount of recovered RNP. In the presence of 0.7 M NaCl the s-value of the complex changes from 70-110S to 40-80S. The RNP structure is stable to mild RNase A or micrococcal nuclease digestion. Transmission electron microscopy reveals the presence of a heterogeneous population of particles with a mean diameter of 300-360 A. The isolated RNP structure differs completely from the well-known monoparticle or polyparticle hnRNP complexes and from the 30S or smaller snRNP particles but could be similar to or identical with the heterogeneous complex described by Jacob et al. [29].
Hatzoglou
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Adamtziki
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Margaritis
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Sekeris
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D000546:Amanitins / Q000494:pharmacology; D000818:Animals; D002499:Centrifugation, Density Gradient; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D008099:Liver / Q000032:analysis / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008970:Molecular Weight; D012313:RNA / Q000302:isolation & purification*; D012332:RNA, Heterogeneous Nuclear / Q000302:isolation & purification*; D012342:RNA, Small Nuclear; D051381:Rats; D011919:Rats, Inbred Strains; D012259:Ribonuclease, Pancreatic; D012261:Ribonucleoproteins / Q000302:isolation & purification*; D012965:Sodium Chloride
D000546:Amanitins; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012332:RNA, Heterogeneous Nuclear; D012342:RNA, Small Nuclear; D012261:Ribonucleoproteins; D012965:Sodium Chloride; D012313:RNA; D012259:Ribonuclease, Pancreatic