Biology:Melanophilin

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Short description: Protein-coding gene in the species Homo sapiens


A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example


Melanophilin is a carrier protein which in humans is encoded by the MLPH gene.[1][2] Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been determined.

Function

This gene encodes a member of the exophilin subfamily of Rab effector proteins. The protein forms a ternary complex with the small Ras-related GTPase Rab27A in its GTP-bound form and the motor protein myosin Va.[3] A similar protein complex in mouse functions to tether pigment-producing organelles called melanosomes to the actin cytoskeleton in melanocytes, and is required for visible pigmentation in the hair and skin.[4]

In melanocytic cells MLPH gene expression may be regulated by MITF.[5]

Clinical significance

A mutation in this gene results in Griscelli syndrome type 3, which is characterized by a silver-gray hair color and abnormal pigment distribution in the hair shaft.

Mutations in melanophilin cause the "dilute" coat color phenotype in dogs[6] and cats.[7] Variation in this gene appears to have been a target for recent natural selection in humans, and it has been hypothesized that this is due to a role in human pigmentation.[8]

References

  1. "Mutations in Mlph, encoding a member of the Rab effector family, cause the melanosome transport defects observed in leaden mice". Proc. Natl. Acad. Sci. U.S.A. 98 (18): 10238–43. August 2001. doi:10.1073/pnas.181336698. PMID 11504925. Bibcode2001PNAS...9810238M. 
  2. "A family of Rab27-binding proteins. Melanophilin links Rab27a and myosin Va function in melanosome transport". J. Biol. Chem. 277 (28): 25423–30. July 2002. doi:10.1074/jbc.M202574200. PMID 11980908. 
  3. "Melanophilin directly links Rab27a and myosin Va through its distinct coiled-coil regions". FEBS Lett. 517 (1–3): 233–8. April 2002. doi:10.1016/S0014-5793(02)02634-0. PMID 12062444. 
  4. "Entrez Gene: MLPH Melanophilin". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=79083. 
  5. "Novel MITF targets identified using a two-step DNA microarray strategy". Pigment Cell Melanoma Res. 21 (6): 665–76. 2008. doi:10.1111/j.1755-148X.2008.00505.x. PMID 19067971. 
  6. "A noncoding melanophilin gene (MLPH) SNP at the splice donor of exon 1 represents a candidate causal mutation for coat color dilution in dogs". J. Hered. 98 (5): 468–73. 2007. doi:10.1093/jhered/esm021. PMID 17519392. 
  7. "A homozygous single-base deletion in MLPH causes the dilute coat color phenotype in the domestic cat". Genomics 88 (6): 698–705. December 2006. doi:10.1016/j.ygeno.2006.06.006. PMID 16860533. 
  8. "Signals of recent positive selection in a worldwide sample of human populations". Genome Res. 19 (5): 826–37. May 2009. doi:10.1101/gr.087577.108. PMID 19307593. 

Further reading

External links

This article incorporates text from the United States National Library of Medicine, which is in the public domain.