Phosphoproteomics Analysis Reveals a Pivotal Mechanism Related to Amino Acid Signals in Goat Fetal Fibroblast

Abstract

In addition to serving as the building blocks for protein synthesis, amino acids serve as critical signaling molecules in cells. However, the mechanism through which amino acid signals are sensed in cells is not yet fully understood. This study examined differences in the phosphorylation levels of proteins in response to amino acid signals in Cashmere goat fetal fibroblasts (GFb). Amino acid deficiency was found to induce autophagy and attenuate mammalian/mechanistic target of rapamycin complex (mTORC1)/Unc-51-like autophagy activating kinase 1 (ULK1) signaling in GFb cells. A total of 144 phosphosites on 102 proteins positively associated with amino acid signaling were screened using phosphorylation-based proteomics analysis. The mitogen-activated protein kinase (MAPK) signaling pathway was found to play a potentially important role in the interaction network involved in the response to amino acid signals, according to gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and MAPK1/3 may serve as a central hub for the entire network. Motif analysis identified three master motifs, xxx_S_Pxx, xxx_S_xxE, and xxx_S_xDx, which were centered on those phosphosites at which phosphorylation was positively regulated by amino acid signaling. Additionally, the phosphorylation levels of three membrane proteins, the zinc transporter SLC39A7, the sodium-dependent neutral amino acid transporters SLC1A5 and SLC38A7, and three translation initiation factors, eukaryotic initiation factor (eIF)5B, eIF4G, and eIF3C, were positively regulated by amino acid signals. These pivotal proteins were added to currently known signaling pathways to generate a novel model of the network pathways associated with amino acid signals. Finally, the phosphorylation levels of threonine 203 and tyrosine 205 on MAPK3 in response to amino acid signals were examined by western blot analysis, and the results were consistent with the data from the phosphoproteomics analysis. The findings of this study provide new evidence and insights into the precise mechanism through which amino acid signals are sensed and conducted in Cashmere goat fetal fibroblasts.

Phosphoproteomics Profile of Chicken Cecum in the Response to Salmonella enterica Serovar Enteritidis Inoculation

“…Additionally, there has been little research to reveal the regulation mechanism of chicken cecum infected with S. Enteritidis in the phosphorylation levels of proteins. There has been a large amount of research on phosphorylated proteomics in human disease [21][22][23][24], bacteria [25], geese [26], goats [27,28], cattle [29], rats, and mice [30][31][32][33]. There were 62 phosphosites on 43 phosphoproteins which were determined to be up-regulated while 113 on 80 phosphoproteins were down-regulated in the research by Huang et al [34]; the up-regulated phosphoproteins were fewer than the down-regulated phosphoproteins.…”

Comparative genomic studies of Tomtom and Nuaimi sheep breeds of Bahrain, and Asian and European sheep breeds revealed selection signatures

“…In Nuaimi/Zel breeds comparison the selection signatures suggested the pyridoxal dependent decarboxylase domain containing 1 (PDXDC1, chr-24) gene to be a candidate gene that may act in the developmental process when comparing the two breeds. Zheng et al, [35] concluded a strong correlation between PDXDC1 gene and the amino acid expression in goat fetal broblast. Moreover, Rrn3 gene is an important mammalian RNA polymerase formation that acting as an initiation factor for the RNA polymerase transcription [36].…”