关键词: FNDC5蛋白, 起始翻译, Irisin, non-ATG

Abstract: Irisin, identified water soluble polypeptide fragments, also called muscle factor, has been shown to be secreted from fibronectin type III domain containing protein 5 (FNDC5) of skeletal muscle by an unknown protease, promotes the white adipose tissue convert to brown adipose tissue, closely associated with diabetes. In this paper we investigated the initiated translation mechanism of human Irisin precursor proteins FNDC5. In order to determine the initiated translation site of human Irisin precursor FNDC5, we investigated the Top 20 FNDC5 homologous sequences by evolutionary analysis and motif identification. Then, we analyzed the sequence and function of the non-ATG translation initiation in common by GO enrichment, hairpin structure and context analysis, which explained the features of ATA translation initiation. The results showed that: Compared with other species, the initiator codon of human Irisin precursor proteins FNDC5 is ATA. Human genome non-ATG-initiated translation has context preference that the purine -3 position (A/G) and guanidine +4 (C) position and special location of the hairpin structure. However, the context of the different initiation codon have different preferences. The function of human genome-wide non-ATG protein focus on metabolic process, biological regulation, nucleotide transcription factors, linking, etc, which are regulatory proteins. Results indicated that, human Irisin precursor proteins FNDC5 initiated translation have potential optimal ATA context, which might be a unique non-ATG initiated translation mechanism. Proteins, non-ATG initial translation in human, which may play an important role in the regulation of human metabolization.

Key words: FNDC5 protein, initial translation, Irisin, non-ATG