Proteomic analysis of coarse and fine skin tissues of Liaoning cashmere goat.

Proteomics is the study of all proteins expressed by a cell or even an organism. However, knowledge of proteins that regulate the fineness of cashmere is limited. Liaoning cashmere goat (LCG) is a valuable genetic resource of China. The skin samples of Liaoning cashmere goats during the growing period were collected, performed tandem mass tag (TMT) method, and identified 117 differentially expressed proteins in CT_LCG (course type) and FT_LCG (fine type). To verify proteins differentially expressed in LCG, we performed PRM validation on three candidate proteins (ALB, SDC1, and ITGB4) in CT-LCG and FT-LCG. Furthermore, primary metabolic process and lysosome are most enriched in the GO and KEGG pathways, respectively. In addition, we also derived a protein-protein interaction (PPI) regulatory network from the perspective of bioinformatics. This study sought to elucidate the molecular mechanism of differential proteins regulating cashmere fineness of Liaoning cashmere goats by using TMT quantitative proteomics analysis. Differentially expressed proteins ALB and SDC1 may regulate cashmere fineness; ITGB4 can become a promising protein for further study. They can be used as key proteins to lay a foundation for studying cashmere fineness of Liaoning cashmere goats.