Notch signal path

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Structure of the ligand binding region of the human NOTCH-1 receptor

The Notch signaling pathway is a widely used and highly conserved signal transduction pathway through which cells can respond to external signals . The signal path is named after its receptor “Notch”, which binds the membrane-bound ligand “Delta” on the surface of another cell. Notch is a transmembrane protein with only one transmembrane domain and one large extracellular domain.

functionality

The Notch signaling pathway is based on proteolysis and is activated by the binding of the ligand Delta to the Notch receptor . The Notch receptor is proteolytically cut three times, the first time in the Golgi apparatus and then two more times after Delta has bound. First, the extracellular domain near the plasma membrane is split off. Then the cytoplasmic part of the membrane-bound Notch receptor is separated by another enzyme (probably presenilin -1) and can now diffuse freely into the cell nucleus, where the fragment is in a complex, together with other regulatory proteins, to the CSL protein - so named as a combination of CBF-1 in mammals, suppressor of hairless in the fruit fly ( Drosophila melanogaster ) and lag-1 in nematodes ( Caenorhabditis elegans ) - binds and thus regulates the expression of notch response genes.

Occurrence

The Notch signaling pathway is involved in the development of most tissues in the animal embryo , and it has been particularly well studied in nerve cells. Delta-notch interactions mediate lateral inhibition , in which each cell takes information from the cells around it into account for its own fate. In other cells, Notch can also help synchronize development processes.

discovery

The eponymous fruit fly

The gene for the Notch receptor was founded in 1916 by Thomas Hunt Morgan discovered that a mutation in the fruit fly Drosophila melanogaster described, the notches ( English had "notches") on their wings

Individual evidence

  1. ↑ Emma R. Andersson, Rickard Sandberg, Urban Lendahl: Notch signaling: simplicity in design, versatility in function . In: Development (Cambridge, England) . tape 138 , no. 17 , 2011, ISSN  1477-9129 , p. 3593-3612 , doi : 10.1242 / dev.063610 , PMID 21828089 .
  2. ↑ Thomas Hunt Morgan : A Critique of the Theory of Evolution. Lectures delivered at Princeton University February 24, March 1, 8, 15, 1916. (1916) London: Princeton University Press. Fig. (B) in Fig. 53. Group I. Text on page 105

See also

literature

  • Bruce Alberts et al. a .: Molecular Biology of the Cell. 4th edition. Garland Science, New York 2002, ISBN 0-8153-4072-9 .