Midbody (cell biology)

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The midbody is a transient structure found in mammalian cells and is present near the end of cytokinesis just prior to the complete separation of the dividing cells. The structure was first described by Walther Flemming in 1891.[1]

Structure[edit]

A middle stage midbody stained with tubulin

The midbody structure contains bundles of microtubules derived from the mitotic spindle which compacts during the final stages of cell division. It has a typical diameter of 1 micrometre and a length of 3 to 5 micrometres.[2] Aside from microtubules it also contains various proteins involved in cytokinesis, asymmetric cell division, and chromosome segregation.

The midbody is important for completing the final stages of cytokinesis, a process called abscission.[3] During symmetric abscission, the midbody is severed at each end and released into the cellular environment.

Role in intercellular signalling[edit]

It was long assumed that the midbody was simply a structural part of cytokinesis, and was totally degraded with the completion of mitosis. However, it is now understood that post-abscission, the midbody is converted into an endosome-like signalling molecule, and can be internalised by nearby cells.[4]

This endosome is marked by MKLP1, and can persist for up to 48 hours once internalised into another cell.[4] It is coated in Actin, which is slowly degraded by the internalising cell.

Related proteins[edit]

References[edit]

  1. ^ Paweletz N (January 2001). "Walther Flemming: pioneer of mitosis research". Nature Reviews. Molecular Cell Biology. 2 (1): 72–75. doi:10.1038/35048077. PMID 11413469. S2CID 205011982.
  2. ^ Mullins JM, McIntosh JR (September 1982). "Isolation and initial characterization of the mammalian midbody". The Journal of Cell Biology. 94 (3): 654–661. doi:10.1083/jcb.94.3.654. PMC 2112229. PMID 7130277.
  3. ^ Skop AR, Liu H, Yates J, Meyer BJ, Heald R (July 2004). "Dissection of the mammalian midbody proteome reveals conserved cytokinesis mechanisms". Science. 305 (5680): 61–66. Bibcode:2004Sci...305...61S. doi:10.1126/science.1097931. PMC 3679889. PMID 15166316.
  4. ^ a b Peterman E, Gibieža P, Schafer J, Skeberdis VA, Kaupinis A, Valius M, et al. (July 2019). "The post-abscission midbody is an intracellular signaling organelle that regulates cell proliferation". Nature Communications. 10 (1): 3181. Bibcode:2019NatCo..10.3181P. doi:10.1038/s41467-019-10871-0. PMC 6639393. PMID 31320617.
  5. ^ a b c Iwamori T, Iwamori N, Ma L, Edson MA, Greenbaum MP, Matzuk MM (May 2010). "TEX14 interacts with CEP55 to block cell abscission". Molecular and Cellular Biology. 30 (9): 2280–2292. doi:10.1128/MCB.01392-09. PMC 2863583. PMID 20176808.
  6. ^ Capalbo L, Bassi ZI, Geymonat M, Todesca S, Copoiu L, Enright AJ, et al. (October 2019). "The midbody interactome reveals unexpected roles for PP1 phosphatases in cytokinesis". Nature Communications. 10 (1): 4513. Bibcode:2019NatCo..10.4513C. doi:10.1038/s41467-019-12507-9. PMC 6778137. PMID 31586073.