Agouti: From mouse to man, from skin to fat
The agouti protein regulates pigmentation in the mouse hair follicle producing a black hair with a subapical yellow band. Its effect on pigmentation is achieved by antagonizing the binding of alpha-melanocyte stimulating hormone (alpha-MSH) to melanocortin 1 receptor (Mc1r), switching melanin synthesis from eumelanin (black/brown) to phaeomelanin (red/yellow). Dominant mutations in the non-coding region of mouse agouti cause yellow coat colour and ectopic expression also results in obesity, type 11 diabetes, increased somatic growth and tumourigenesis. At least some of these pleiotropic effects can be explained by antagonism of other members of the melanocortin receptor family by agouti protein. The yellow coat colour is the result of agouti chronically antagonizing the binding of alpha-MSH to Mc1r and the obese phenotype results from agouti protein antagonizing the binding of alpha-MSH to Mc3r and/or Mc4r. Despite the existence of a highly homologous agouti protein in humans, agouti signal protein (ASIP), its role has yet to be defined. However it is known that human ASIP is expressed at highest levels in adipose tissue where it may antagonize one of the melanocortin receptors. The conserved nature of the agouti protein combined with the diverse phenotypic effects of agouti mutations in mouse and the different expression patterns of human and mouse agouti, suggest ASIP may play a role in human energy homeostasis and possibly human pigmentation.
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|Item Type:||Journal Article|
|Additional Information:||For more information, please refer to the journal’s website (see hypertext link) or contact the author. Author contact details: firstname.lastname@example.org|
|Keywords:||Obesity, Pigmentation, Melanocortin 1 receptor, Melanocortin 4 receptor|
|Divisions:||Current > Research Centres > CRC for Diagnostics
Past > QUT Faculties & Divisions > Faculty of Science and Technology
Current > Institutes > Institute of Health and Biomedical Innovation
|Copyright Owner:||Copyright 2002 Blackwell Publishing|
|Copyright Statement:||The definitive version is available at www.blackwell-synergy.com|
|Deposited On:||06 Jul 2007|
|Last Modified:||21 Apr 2010 16:24|
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