In silico genomic and proteomic analyses of three heat shock proteins (HSP70, HSP90-a, and HSP90-b) in even-toed ungulates

BACKGROUND Heat shock proteins (HSPs) play important roles in the responses to different environmental stresses. In this study, the genomic and proteomic characteristics of three HSPs (HSP70, HSP90-a and HSP90-b) in five even-toed ungulates (sheep, goats, water buffalo, Zebu cattle and cattle) were analyzed using Multiple sequence alignment, SWISS modeling and phylogenetics analysis tools. RESULTS The bioinformatic analysis revealed that the HSP70 gene in cattle, Zebu cattle, and goat is located on chromosome 23, and is intronless, while in water buffalo and sheep it is located on chromosomes 2 and 20, respectively, and contains two exons linked by one intron. The HSP90-a gene is located on chromosome 21 in cattle, Zebu cattle, and goat, while in water buffalo and sheep it is located on chromosomes 20 and 18, respectively. The HSP90-b gene is located on the same chromosome as the HSP70 gene and contains 12 exons interspersed by 11 introns in all studied animals. In silico Expasy translate tool analysis revealed that HSP70, HSP90-a and HSP90-b encode 641, 733, and 724 amino acids, respectively. The data revealed that goat HSP70 protein has seven variable amino acid residues, while in both sheep and cattle only one such amino acid was detected. CONCLUSIONS This study will be supportive in providing new insights into HSPs for adaptive machinery in these studied animals and selection of target genes for molecular adaptation of livestock

Detection of polymorphisms in the bovine leptin receptor gene affects fat deposition in two Chinese beef cattle breeds.

Leptin receptor (LEPR) gene play a pivotal role in the regulation of fat deposition and energy homeostasis. This study investigated the presence and frequency of polymorphisms of bovine LEPR gene and determine whether the polymorphisms are associated with the fat deposition in two Chinese beef cattle breeds. Quantitative real-time polymerase chain reactions identified that the expression of LEPR gene was highest in the liver and subcutaneous fat. Four single nucleotide polymorphisms (SNPs) were identified including g.24169C > T, g.24256T > A, g.24267 G > C and g.24413T > A. A greater backfat thickness was associated with the AA genotype of g.24256T > A compared to the TT genotype. A greater intramuscular fat content was associated with the GG genotype of g.24267 G > C compared to the CC genotype. Both g.24169C > T and g.24413T > A were not correlated with fat deposition. These results indicated that the SNP g.24256T > A and g.24267 G > C of LEPR gene may be useful markers for genetic improvement of fat deposition in Chinese beef cattle breeds.

Function and characterization of the promoter region of perilipin 1 (PLIN1): Roles of E2F1, PLAG1, C/EBPß, and SMAD3 in bovine adipocytes.

Perilipin 1 (PLIN1) protein, also known as lipid droplet-associated protein, is encoded by the PLIN1 gene and is able to anchor itself to the membranes of lipid droplets. The phosphorylation of PLIN1 is critical for the mobilization of fat in adipose tissue and plays an important role in regulating lipolysis and lipid storage in adipocytes. However, research on the synthesis and lipid metabolism of lipid droplets by PLIN1 in bovine adipocytes is limited. In the present study, we found that bovine PLIN1 was highly expressed in subcutaneous adipose tissue. The highest level of PLIN1 mRNA expression in bovine adipocytes was observed on day 6 of differentiation. Moreover, the cytoplasmic subcellular localization of PLIN1 was observed in bovine preadipocytes. To elucidate the molecular mechanism of bovine PLIN1 transcriptional regulation, we cloned eight fragments containing the 5' regulatory region of the PLIN1 gene. The results showed that the -209/-17 bp region of the bovine PLIN1 gene was the core promoter region. Based on the transcriptional activities of the promoter vector fragments, the luciferase activity of the mutated fragment, the siRNA interference, and the results of the electrophoretic mobility shift assay (EMSA), we identified the binding sites of E2F transcription factor 1 (E2F1), pleiomorphic adenoma gene 1 (PLAG1), CCAAT enhancer binding protein beta (C/EBPß), and SMAD family member 3 (SMAD3) as the transcriptional activators or repressors of the core promoter region. Further experiments confirmed that the knockdown of the PLIN1 gene affected the ability of these transcription factors to regulate the lipid metabolism in bovine adipocytes. In conclusion, our results reveal a potential mechanism for the transcriptional regulation of PLIN1 in bovine adipocytes.