Further studies on the protein moiety in nuclear DNA-like RNA containing complexes

Krichevskaya, A. A.; Georgiev, G.P.

doi:10.1016/0005-2795(69)90129-9

Cited by 55 publications

(8 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Ribonucleoprotein (RNP) particles containing heterogeneous nuclear RNA sedimenting homogeneously at about 30 S have been extracted from the isolated nuclei of many higher vertebrates (19)(20)(21). The protein composition of these 30 S RNP complexes is relatively simple, consisting of multiple copies of only a very few specific polypeptides (21,22). The RNA from 30S complexes contains sequences that hybridize to the moderately repetitive DNA, and includes sequences not present in the cytoplasm (23,24).…”

mentioning

confidence: 99%

Nuclear Ribonucleoprotein Complexes Containing Polyadenylate from Mouse Ascites Cells

Quinlan

Billings

Martin

1974

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Nuclear poly(A)-containing RNA of mouse ascites cells can be extracted in the form of 15-17 S ribonucleoprotein complexes under conditions in which the bulk of the heterogeneous nuclear RNA is released as 30S complexes. The poly(A)-containing fraction of nuclear extracts has been resolved into two distinct components, 15 and 17 S; neither contains the two polypeptides of 30S ribonucleoprotein. The 17 S particle contains approximately six polypeptide species of molecular masses 17,000-30,000 daltons. The 15S complex has four distinct polypeptides of higher molecular mass, including a prominent 80,000-dalton species.In higher eukaryotes the rapidly labeled nuclear RNA, characterized as DNA-like by its base composition and ease of hybridization, is transcribed as large sequences sedimenting heterogeneously in sucrose gradients (heterogeneous nuclear RNA). The bulk of these RNA sequences is rapidly degraded in the nucleus (1-6). Only a relatively small fraction of the rapidly labeled RNA is conserved, reaching the cytoplasm as mRNA. Considerable evidence suggests that mRNA is, in fact, transcribed as part of a much larger nuclear precursor which is cleaved to yield the true messenger (7-9). Some heterogeneous nuclear RNA and most mRNA molecules contain polynucleotide sequences rich in adenylic acid [poly(A)] at the 3'-OH termini (10-14). Poly(A) appears to be a characteristic sequence in all mRNA with the exception of histone mRNA (15, 16). The addition of poly(A) is most likely a post-transcriptional nuclear event (12, 17), occurring before or during the nucleolytic processing of the putative precursors into mRNA.The DNA-like RNA of higher eukaryotes is found both in nuclear and cytoplasmic extracts in a form complexed with specific proteins (18). Ribonucleoprotein (RNP) particles containing heterogeneous nuclear RNA sedimenting homogeneously at about 30 S have been extracted from the isolated nuclei of many higher vertebrates (19-21). The protein composition of these 30 S RNP complexes is relatively simple, consisting of multiple copies of only a very few specific polypeptides (21,22). The RNA from 30S complexes contains sequences that hybridize to the moderately repetitive DNA, and includes sequences not present in the cytoplasm (23, 24). Insofar as DNA-like RNA that is extracted from 30S complexes sediments at only 4-8 S (19, 25), it must be concluded that 30S complexes derive from much larger nuclear ribonucleoprotein complexes.Our interest in the possible role of the 30S RNP complexes in the transport of mRNA from the nucleus to the cytoplasm Isolation of Nuclei and Preparation of Nuclear Extracts. The nature and propagation of the Taper hepatoma ascites cell line have been described (24). All cell fractionation procedures were done at 0-4°. The isolation of nuclei and extraction with buffered salt solution were based on the method of Samarina et al. (19,27) and have been described (21,24). After brief washes in 0.1 M NaCl-10 mM Tris * HCl-1 mM MgCl2 (pH 7) and the same buffer at pH 9, the isolated nuc...

show abstract

mentioning

confidence: 99%

Nuclear Ribonucleoprotein Complexes Containing Polyadenylate from Mouse Ascites Cells

Quinlan

Billings

Martin

1974

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…The addition of urea dissociates informofers into 102 sub-units; in polyacrylamide gel electrophoresis more than 90% of the material may be found in one component with a molecular weight of -40,000 (as determined in the presence of SDS) (see [9] ). Free informofers easily interact with dRNA after removal of the dissociating agent.…”

Section: Resultsmentioning

confidence: 99%

The isolation of informofers free from dRNA

Lukanidin¹,

Аitkhozhinа²,

Kulguskin³

et al. 1971

FEBS Letters

Self Cite

View full text Add to dashboard Cite

“…The dominating protein bands of about 40,000 daltons present in undegraded hnRNP complexes are most probably identical with the 40,000 dalton proteins that are the structural components of the informofer-like 30S particles (23,29). The use of high resolution polyacrylamide gel systems has shown that purified, high-salt-washed 30S particles from a variety of cultured cells contain at least two proteins having almost identical molecular weights around 40,000 daltons (2,11,60).…”

Section: The Proteins In Hnrnp Particlesmentioning

confidence: 97%

“…Samafina and coworkers (5,26,28) proposed that these 30 S subparticles were composed of a residual-stretch of hnRNA attached to a globular protein particle, called an informofer (5,26). An informofer was thought to be a complex of a number of (identical) proteins with a subunit molecular weight of about 40,000 (26,29). The 30 S RNP subparticles show a rather homogeneous peak in sucrose gradients (2,5,26) and electronmicroscopic observations revealed them to be rather homogeneous particles of about 200 -300 A in diameter (26,(30)(31)(32).…”

Section: Isolation Of Hnrnp Particlesmentioning

confidence: 99%

“…Some amino acid compositions of structural proteins in 30S subparticles have been published (2,29). In rat liver the principal component of informofers is a more or less neutral protein (29~), while the most abundant structural proteins in 30S subparticles from HeLa cells are basic polypeptides with a high glycine content and a modified arginine residue (2).…”

Section: The Proteins In Hnrnp Particlesmentioning

confidence: 99%

See 1 more Smart Citation