Genetic diversity of the melanocortin-1 receptor in an admixed population of Rio de Janeiro: Structural and functional impacts of Cys35Tyr variant

PLoS One. 2022 Apr 22;17(4):e0267286. doi: 10.1371/journal.pone.0267286. eCollection 2022.

Abstract

The melanocortin-1 receptor (MC1R) is one of the key proteins involved in the regulation of melanin production and several polymorphisms have been associated with different phenotypes of skin and hair color in human and nonhuman species. Most of the knowledge is centered on more homogeneous populations and studies involving an admixed group of people should be encouraged due to the great importance of understanding the human color variation. This work evaluates the MC1R diversity and the possible impacts of MC1R variants in an admixed sample population of Rio de Janeiro, Brazil, which is a product of Native American, African, and European miscegenation. Sequencing of complete coding region and part of the 3´UTR of MC1R gene identified 31 variants including one insertion and three novel synonymous substitutions in sample population grouped according to skin, hair and eye pigmentation levels. In nonmetric multidimensional scaling analysis (NMDS), three main clusters were identified, in which the Brazilian dark skin group remained in the African cluster whereas the intermediate and the light skin color phenotype in the European one. None gathered with Asians since their immigration to Brazil was a recent event. In silico analyses demonstrated that Cys35Tyr, Ile155Thr and Pro256Ser, found in our population, have a negative effect on receptor function probably due to changes on the receptor structure. Notably, Cys35Tyr mutation could potentially impair agonist binding. Altogether, this work contributes to the understanding of the genetic background of color variation on an admixed population and gives insights into the damaging effects of MC1R variants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brazil
  • Genetic Variation
  • Hair Color* / genetics
  • Humans
  • Phenotype
  • Polymorphism, Genetic
  • Receptor, Melanocortin, Type 1* / genetics

Substances

  • MC1R protein, human
  • Receptor, Melanocortin, Type 1

Grants and funding

(VNM) Pro-Forense Fellowship Grant n° 23038.006844/2014-46 CAPES (PSFCG) FAPERJ, E-26/260043/2019 (RS) was supported by CNPq Grant n° 304156/2016-7, FAPERJ Grant n° 202847/2018. (RSMN) was supported by CAPES Pro-Forense Grant n° 23038006844/2014-46, CNPq Grant n° 312905/2018-1, FAPERJ Grant n° 202532/2019. URL: CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (https://www.gov.br/capes/pt-br/assuntos/editais-capes) CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico (https://www.gov.br/cnpq/pt-br/acesso-a-informacao/bolsas-e-auxilios) FAPERJ- Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (http://www.faperj.br) The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.