Identification and bioinformatics analysis of G-protein-coupled receptors in Aspergillus ochraceus

Abstract:

[Objective] This study aims to predict and analyze the structural characteristics and physicochemical properties of G-protein-coupled receptors (GPCRs) in Aspergillus ochraceus and to explore the clustering of GPCR proteins and their evolutionary relationships with the homologous proteins. The findings are expected to lay a theoretical basis of further research on the locations and functions of GPCRs in A. ochraceus, help inhibit ochratoxin production from the perspective of G protein signaling pathway, and further control mycotoxin contamination in grains. [Methods] Candidate GPCR proteins were screened through BLASTp alignment of A. ochraceus genome against the reported typical GPCR sequences of Aspergillus sp. Conserved domains, especially transmembrane domains, were analyzed by SMART and a variety of software. The physicochemical properties, signal peptides, secondary structures, and subcellular localization of the candidate sequences were further analyzed. Finally, MEGA was used to construct a phylogenetic tree of GPCRs in A. ochraceus and homologous proteins, and the genetic relationship was elucidated. [Results] A total of 15 GPCR proteins with typical seven transmembrane helices were found in A. ochraceus, but they had no signal peptides or transit peptides. They all contained a large proportion of α-helices, and 7 of the 15 proteins were located at the cell membrane. GPCRs in A. ochraceus had close genetic relationship with the homologous sequences in A. flavus and other Aspergillus species. [Conclusion] In this study, the GPCRs in A. ochraceus were predicted for the first time. The structures and physicochemical properties of them and the clustering with homologous proteins were analyzed, laying a theoretical basis for further research on the functions of GPCRs in A. ochraceus.