Evaluation of hypothalamic murine and human melanocortin 3 receptor transcript structure

Abstract

The melanocortin 3 receptor (MC3R) is involved in regulation of energy homeostasis. However, its transcript structure is not well understood. We therefore studied initiation and termination sites for hypothalamic murine Mc3r and human MC3R transcripts. Rapid Amplification of cDNA Ends (RACE) was performed for the 5’ and 3’ ends of murine and human hypothalamic RNA. 5’ RACE experiments using hypothalamic murine RNA indicated mouse hypothalamus expresses two major Mc3r transcription start sites: one with a 5’ UTR approximately 368 bases in length and another previously unknown transcript with a 5’ UTR approximately 440 bases in length. 5’ RACE experiments using human hypothalamic RNA identified a 5’ UTR beginning 533 bases upstream of the start codon with a 248 base splice. 3’ RACE experiments using hypothalamic murine RNA indicated the 3’ UTR terminates approximately 1286 bases after the translational stop codon, with a previously unknown 787 base splice between consensus splice donor and acceptor sites. 3’ RACE experiments using human MC3R transcript indicated the 3’ UTR terminates approximately 115–160 bases after the translational stop codon. These data provide insight into melanocortin 3 receptor transcript structure.

Polymorphisms and mutations in the melanocortin-3 receptor and their relation to human obesity

“…Studies have evaluated the transcript structure of murine Mc3r and human MC3R by examining its untranslated regions (UTRs) [13, 14], which can play important roles in gene expression, mRNA stability, and translational efficiency. Research from our group [14] demonstrated that the murine Mc3r 5′ UTR has two transcription start sites: one 368 bases upstream of the translation start site and another 440 bases upstream, with putative initiator sequences associated with each start site.…”

“…Research from our group [14] demonstrated that the murine Mc3r 5′ UTR has two transcription start sites: one 368 bases upstream of the translation start site and another 440 bases upstream, with putative initiator sequences associated with each start site. The murine Mc3r 3′ UTR terminates 1286 bases after the translational stop codon, but with a 787 base splice between consensus splice donor and acceptor sites from 171 bases to 958 bases downstream of the stop codon.…”

“…The human MC3R 5′ UTR, on the other hand, has a transcription start site 527–544 bases upstream of the classical translation start site, with most transcripts starting 533 bases upstream, near a putative initiator sequence. There is also a 248 base splice from 140 to 388 bases upstream of the start codon between consensus splice donor and acceptor sites [13, 14]. The human MC3R 3′ UTR was found to end only 115–160 bases after the translational stop codon [13, 14].…”

“…There is also a 248 base splice from 140 to 388 bases upstream of the start codon between consensus splice donor and acceptor sites [13, 14]. The human MC3R 3′ UTR was found to end only 115–160 bases after the translational stop codon [13, 14]. The human MC3R has more than one potential start site for translation, with additional in-frame ATGs located 37 and 109 codons downstream.…”

Genomic Databases and Softwares: In Pursuit of Biological Relevance through Bioinformatics

“…Summary of some bioinformatics tools utilized for the predicting the biological applications of nucleic acids and proteins[42][43][44]50,51,54,[68][69][70][71][72][73][74].Genomic Databases (GenBank, EMBL, DDBJ, Unigene)Genetic testing for identifying chromosomes, genes or proteins Search for nucleic acid/ protein sequences using BLAST…”