TRPN

Structure

A structure of NOMPC was published in 2017, solved using electron cryo-microscopy. X-ray crystallography studies of channel segments cloned from fruit flies and zebrafish have led to the hypothesis that multiple ankyrin repeats at TRPN's N-terminus are involved in the gating of the channel pore.{{Cite journal | doi-access = free | doi-access = free

Function

As a mechanoreceptor, TRPN responds to impinging mechanical forces. Studies in TRPN deficient adult fruit flies and larvae have shown that these null mutants have severe difficulty moving, which suggests a role for TRPN in proprioception.{{Cite journal | editor1-last = Gonzalez | editor1-first = Cayetano | article-number = e11012 | doi-access = free | doi-access = free

Studies in worms have shown that TRPN mutants have locomotion defects, as well as a decreased basal slowing response, which is a reduction in rate of motion that is induced by contact with a food source. This result further strengthens the hypothesis that TRPN is vital to proprioception. Electrophysiological studies of single channels in worms have shown that TRPN responds to mechanical stimuli and has a preference for sodium ions,{{Cite journal

Studies in zebrafish larvae have also shown that morpholino-mediated knockdown of TRPN function result in deafness as well as imbalance, suggesting a dual role in hearing as well as proprioception. Immunostaining studies in frog embryos have shown localization of TRPN at the tips of mechanosensory cilia in the lateral line, hair cells and ciliated epidermal cells, suggesting a role in a variety of mechanosensory functions. TRPN localizes to the kinocilia, not stereocilia, of amphibian hair cells, suggesting the presence of two distinct classes of mechanosensitive channel.

TRPN has the capability of performing a variety of roles in mechanosensory systems.

Genes

Genomic data from a variety of organisms show that TRPN is present in most animals, but it is absent in all amniotes. In most animals the number of ankyrin repeats is between 28 and 29.

The following is a list of genes encoding TRPN organized by the organism in which they are found. Gene names are specific to the organism and to the way in which they were discovered, which is why the gene name may not explicitly be "TRPN". Links to the NCBI Gene database are included whenever possible.

Fruit fly (''Drosophila melanogaster'')

• nompC

Nematode worm (''Caenorhabditis elegans'')

• trp-4

African clawed frog (''Xenopus laevis'')

• nompc

Zebrafish (''Danio rerio'')

• trpn1

References

References

1. (July 2017). "Electron cryo-microscopy structure of the mechanotransduction channel NOMPC". Nature.
2. (June 2015). "The Rise and Fall of TRP-N, an Ancient Family of Mechanogated Ion Channels, in Metazoa". Genome Biology and Evolution.
3. [https://www.ncbi.nlm.nih.gov/gene/33768 NCBI Genbank entry]
4. [https://www.ncbi.nlm.nih.gov/gene/190574 NCBI Genbank entry]
5. [https://www.ncbi.nlm.nih.gov/gene/734212 NCBI Genbank entry]
6. [https://www.ncbi.nlm.nih.gov/gene/368273 NCBI Genbank entry]