Ribonucleoprotein

Ribonucleoprotein (RNP) is a nucleoprotein that contains RNA, i.e. it is an association that combines ribonucleic acid and protein together (referred also as protein-RNA complexes). A few known examples include the ribosome, the enzyme telomerase, vault ribonucleoproteins, RNase P, hnRNP and small nuclear RNPs (snRNPs), which are implicated in pre-mRNA splicing (spliceosome) and are among the main components of the nucleolus.

Currently, over 2000 RNPs can be found in PDB database. Based on known structures some common features of protein-RNA interface were deduced.[1] For example, RNP in snRNPs has an RNA-binding motif in its RNA-binding protein. Aromatic amino acid residues in this motif result in stacking interactions with RNA. Lysine residues in the helical portion of RNA-binding proteins help to stabilize interactions with nucleic acids. This nucleic acid binding is strengthened by electrostatic attraction between the positive lysine side chains and the negative nucleic acid phosphate backbones. Additionally, it is possible to model RNPs computationally.[2]

RNPs among many can play an important role in influenza A virus replication. The viral RNA is transcribed into mRNAs by the RNA polymerase attached to the RNPs.[3]

'RNP' can also refer to ribonucleoprotein particles, distinct intracellular foci for post-transcriptional regulation.

Anti-RNP antibodies

Anti-RNP antibodies are autoantibodies associated with mixed connective tissue disease and are also detected in nearly 40% of Lupus erythematosus patients. Two types of anti-RNP antibodies are closely related to Sjögren's syndrome: SS-A (Ro) and SS-B (La). Autoantibodies against snRNP are called Anti-Smith antibodies and are specific for SLE.

List of RNPs

This is a (partial) list of ribonucleoprotein families:

References

  1. ↑ Lewis, B. A.; Walia, R. R.; Terribilini, M; Ferguson, J; Zheng, C; Honavar, V; Dobbs, D (2011). "PRIDB: A Protein-RNA interface database". Nucleic Acids Research 39 (Database issue): D277–82. doi:10.1093/nar/gkq1108. PMC 3013700. PMID 21071426.
  2. ↑ Tuszynska, I; Matelska, D; Magnus, M; Chojnowski, G; Kasprzak, J. M.; Kozlowski, L. P.; Dunin-Horkawicz, S; Bujnicki, J. M. (2014). "Computational modeling of protein-RNA complex structures". Methods 65 (3): 310–9. doi:10.1016/j.ymeth.2013.09.014. PMID 24083976.
  3. ↑ Baudin, F; Bach, C; Cusack, S; Ruigrok, R. W. (1994). "Structure of influenza virus RNP. I. Influenza virus nucleoprotein melts secondary structure in panhandle RNA and exposes the bases to the solvent". The EMBO Journal 13 (13): 3158–65. PMC 395207. PMID 8039508.

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