Dynamine

from Wikipedia, the free encyclopedia

Dynamins are enzymes , more precisely GTPases , that mediate a form of endocytosis in the eukaryotic cell . Dynamins are primarily involved in the constriction of newly formed vesicles from the membrane of a cell compartment. However, they also play a role in transporting the vesicle to and fusing with the target membrane. This is usually the membrane of the Golgi apparatus or the cell membrane. Furthermore, dynamines play a role in the division of cell organelles and cytoplasm ( cytokinesis ) as well as in the defense against microbial pathogens . Mutations in the gene coding for Dynamin-2 can cause rare hereditary myopathies in humans.

Dynamins belong to the Dynamin protein superfamily, which, in addition to the classic dynamines, also includes Dynamin-like proteins, Mx proteins, OPAs (short for “optic atrophy”), mitofusins ​​and guanylate-binding proteins. Includes proteins (GBPs). Dynamin itself is a 96  kDa enzyme that was discovered in the search for microtubule-related motor proteins in cattle brains . Dynamin has been extensively researched in the context of clathrin- mediated vesicle formation on cell membranes.

function

When a vesicle protrudes from a membrane, Dynamin forms a spiral structure around the neck of the budding vesicle. Driven by GTP hydrolysis, the coil expands lengthwise, wrapping itself more tightly around the neck of the vesicle. This ultimately leads to the constriction of the vesicle membrane from the original membrane. (Pictures: see under web links)

The narrowing of the dynamin spiral is partly due to a rotating movement of the dynamin, which is strictly dependent on the GTPase activity. Dynamin is present as a right-handed helix and the rotational movement due to GTP cleavage is also to the right, so that the Dynamin spiral is shortened, like a telephone cable that is twisted. Dynamin is the only known “molecular motor” that performs such a rotary motion.

Isoforms

Three different Dynamin genes are known in mammals : Dynamin 2 is expressed in most cell types, Dynamin 1 is found in neurons and neuroendocrine cells, and Dynamin 3 is particularly strongly expressed in the testes , but also in the heart, brain and lungs .

epilepsy

New studies indicate that inhibiting the interaction between Dynamin and Syndapin leads to the disruption of communication between nerve cells . This could be a possible point of attack in the treatment of epilepsies , amnesia or schizophrenia in the future .

Web links

Commons : Dynamins  - collection of images, videos and audio files

swell

  1. ^ A b J.R. Henley, H. Cao, MA McNiven: Participation of dynamin in the biogenesis of cytoplasmic vesicles. In: FASEB journal: official publication of the Federation of American Societies for Experimental Biology. Volume 13 Suppl 2, December 1999, pp. S243-S247. PMID 10619136 . (Review).
  2. ↑ a b Hinshaw, J. “Dynamin overview: The Role of Dynamin in Membrane Fission”. National institute of diabetes & digestive & kidney diseases, Laboratory of cell biochemistry and biology. accessed 021806.
  3. ↑ a b Urrutia, R., Henley, JR, Cook, T., McNiven, MA (1997). "The dynamins: Redundant or distinct functions for an expanding family of related GTPases?" Proc. Natl. Acad. Sci. USA , Vol. 94, 377-384.
  4. ↑ a b c McMahon. (2004). Researching Endocytic Mechanisms: Dynamin :. ( Memento of the original from March 5, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Accompaniment of Nature Reviews on Molecular Cell Biology, 5, 133-147. @1@ 2Template: Webachiv / IABot / www.endocytosis.org
  5. ↑ Roux A et al. GTP-dependent twisting of dynamin implicates constriction and tension in membrane fission. Nature. 2006 May 25; 441 (7092): 528-31. PMID 16648839 .
  6. ↑ Chappie JS, Acharya S, Liu YW, Leonard M, Pucadyil TJ, Schmid SL: An intramolecular signaling element that modulates dynamin function in vitro and in vivo . In: Mol. Biol. Cell . 20, No. 15, August 2009, pp. 3561-71. doi : 10.1091 / mbc.E09-04-0318 . PMID 19515832 . PMC 2719574 (free full text).
  7. ↑ Epilepsy In The Media - Brain Cell Communication Method Discovered . epilepsy action . June 2006. Archived from the original on December 15, 2007. Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved November 11, 2007. @1@ 2Template: Webachiv / IABot / www.epilepsy.org.uk