Polysome

This article is about the term in cell biology. For the term in crystallography, see Polysome (crystallography).
Several ribosomes synthesizing a polypeptide on the same mRNA strand

A polyribosome (or polysome or ergosome) is a group of ribosomes bound to an mRNA molecule like “beads” on a “thread”.[1] It consists of a complex of an mRNA molecule and two or more ribosomes that act to translate mRNA instructions into polypeptides. Originally coined "ergosomes" in 1963, they were further characterized by Jonathan Warner, Paul M. Knopf,[2] and Alex Rich.

Polysomes are formed during the elongation phase when ribosomes and elongation factors synthesize the encoded polypeptide. Multiple ribosomes move along the coding region of mRNA, creating a polysome. The ability of multiple ribosomes to function on an mRNA molecule explains the limited abundance of mRNA in the cell.[3] Polyribosome structure differs between prokaryotic polysomes, eukaryotic polysomes, and membrane bound polysomes.[1] Polysome activity can be used to measure the level of gene expression through a technique called polysomal profiling.[4]

  1. ^ a b Afonina ZA, Shirokov VA (January 2018). "Three-Dimensional Organization of Polyribosomes- A Modern Approach". Biochemistry. Biokhimiia. 83 (Suppl 1): S48–S55. doi:10.1134/S0006297918140055. PMID 29544430. S2CID 3745602.
  2. ^ Cambra K (Spring 2017). "Paul M. Knopf, PhD". Brown Medicine. Brown University. Retrieved 24 July 2017.
  3. ^ King HA, Gerber AP (January 2016). "Translatome profiling: methods for genome-scale analysis of mRNA translation". Briefings in Functional Genomics. 15 (1): 22–31. doi:10.1093/bfgp/elu045. PMID 25380596.
  4. ^ Li S, Le B, Ma X, Li S, You C, Yu Y, et al. (December 2016). Qi J (ed.). "Biogenesis of phased siRNAs on membrane-bound polysomes in Arabidopsis". eLife. 5: e22750. doi:10.7554/eLife.22750. PMC 5207768. PMID 27938667.