hnRNP particles

Samarina, O. P.

doi:10.1002/bies.950180712

Cited by 8 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, addition of RNAse inhibitors re-distributed the 40S peak to a series of distinct peaks of higher density, suggesting a beads-on-a-string-like arrangement of 40S hnRNP particles on RNA ( 25 ). Consistent with this idea, the lengths of the RNA fragments extracted from the higher density peaks also increased in increments of about 700 nucleotides per additional 40S hnRNP particle ( 24 , 25 ). Moreover, in RNase treated nuclear extracts, hnRNP particles were reconstituted upon addition of in vitro transcribed RNA of about 700 nucleotides ( 26 ).…”

Section: Introductionsupporting

confidence: 59%

“…40S hnRNP particles were initially isolated from rat liver nuclear extracts and shown to sediment as a major peak at 40S on sucrose density gradients, ( 21 ). This peak is composed mainly of single spherical particles with a diameter of about 20 nm ( 22 ), initially referred to as ‘informofers’ ( 23 ) and later termed ‘40S hnRNP particles’ ( 24 ). Interestingly, addition of RNAse inhibitors re-distributed the 40S peak to a series of distinct peaks of higher density, suggesting a beads-on-a-string-like arrangement of 40S hnRNP particles on RNA ( 25 ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

40S hnRNP particles are a novel class of nuclear biomolecular condensates

Domanski

Dedic

Pérez

et al. 2022

Nucleic Acids Research

View full text Add to dashboard Cite

Heterogenous nuclear ribonucleoproteins (hnRNPs) are abundant proteins implicated in various steps of RNA processing that assemble on nuclear RNA into larger complexes termed 40S hnRNP particles. Despite their initial discovery 55 years ago, our understanding of these intriguing macromolecular assemblies remains limited. Here, we report the biochemical purification of native 40S hnRNP particles and the determination of their complete protein composition by label-free quantitative mass spectrometry, identifying A-group and C-group hnRNPs as the major protein constituents. Isolated 40S hnRNP particles dissociate upon RNA digestion and can be reconstituted in vitro on defined RNAs in the presence of the individual protein components, demonstrating a scaffolding role for RNA in nucleating particle formation. Finally, we revealed their nanometer scale, condensate-like nature, promoted by intrinsically disordered regions of A-group hnRNPs. Collectively, we identify nuclear 40S hnRNP particles as novel dynamic biomolecular condensates.

show abstract

Section: Introductionsupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

40S hnRNP particles are a novel class of nuclear biomolecular condensates

Domanski

Dedic

Pérez

et al. 2022

Nucleic Acids Research

View full text Add to dashboard Cite

show abstract

“…In eukaryotic cells, all mRNAs and their precursors are permanently associated with various proteins to form heterogeneous nuclear RNPs (hnRNPs) in the nucleus and translatable (polysomal) and untranslatable free messenger RNPs (mRNPs) in the cytoplasm (1,2). The hnRNP proteins pack pre-mRNAs (mRNA precursors), regulate the pre-mRNA processing and participate in mRNA transport from the nucleus to the cytoplasm (3).…”

Section: Introductionmentioning

confidence: 99%

Structural organization of mRNA complexes with major core mRNP protein YB-1

Skabkin¹

2004

Nucleic Acids Research

136

118

View full text Add to dashboard Cite

YB-1 is a universal major protein of cytoplasmic mRNPs, a member of the family of multifunctional cold shock domain proteins (CSD proteins). Depending on its amount on mRNA, YB-1 stimulates or inhibits mRNA translation. In this study, we have analyzed complexes formed in vitro at various YB-1 to mRNA ratios, including those typical for polysomal (translatable) and free (untranslatable) mRNPs. We have shown that at mRNA saturation with YB-1, this protein alone is sufficient to form mRNPs with the protein/RNA ratio and the sedimentation coefficient typical for natural mRNPs. These complexes are dynamic structures in which the protein can easily migrate from one mRNA molecule to another. Biochemical studies combined with atomic force microscopy and electron microscopy showed that mRNA-YB-1 complexes with a low YB-1/mRNA ratio typical for polysomal mRNPs are incompact; there, YB-1 binds to mRNA as a monomer with its both RNA-binding domains. At a high YB-1/mRNA ratio typical for untranslatable mRNPs, mRNA-bound YB-1 forms multimeric protein complexes where YB-1 binds to mRNA predominantly with its N-terminal part. A multimeric YB-1 comprises about twenty monomeric subunits; its molecular mass is about 700 kDa, and it packs a 600-700 nt mRNA segment on its surface.

show abstract

Problems and paradigms: Multifunctional proteins suggest connections between transcriptional and post‐transcriptional processes

Ladomery¹

1997

BioEssays

View full text Add to dashboard Cite

Recent findings indicate that substantial cross-talk may exist between transcriptional and post-transcriptional processes. Firstly, there are suggestions that specific promoters influence the post-transcriptional fate of transcripts, pointing to communication between protein complexes assembled on DNA and nascent pre-mRNA. Secondly, an increasing number of proteins appear to be multifunctional, participating in transcriptional and post-transcriptional events. The classic example is TFIIIA, required for both the transcription of 5S rRNA genes and the packaging of 5S rRNA. TFIIIA is now joined by the Y-box proteins, which bind DNA (transcription activation and repression) and RNA (mRNA packaging). Furthermore, the tumour suppressor WT1, at first thought to be a typical transcription factor, may also be involved in splicing; conversely, hnRNP K, a bona fide pre-mRNA-binding protein, appears to be a transcription factor. Other examples of multifunctional proteins are mentioned: notably PTB, Sxl, La and PU.1. It is now reasonable to assert that some proteins, which were first identified as transcription factors, could just as easily have been identified as splicing factors, hnRNP, mRNP proteins and vice versa. It is no longer appropriate to view gene expression as a series of compartmentalised processes; instead, multifunctional proteins are likely to co-ordinate different steps of gene expression.

show abstract

hnRNP particles

Cited by 8 publications

References 22 publications

40S hnRNP particles are a novel class of nuclear biomolecular condensates

40S hnRNP particles are a novel class of nuclear biomolecular condensates

Structural organization of mRNA complexes with major core mRNP protein YB-1

Problems and paradigms: Multifunctional proteins suggest connections between transcriptional and post‐transcriptional processes

Contact Info

Product

Resources

About