Tissue expression profiles and transcriptional regulation of elongase of very long chain fatty acid 6 in bovine mammary epithelial cells

Abstract

In mammals, very long chain fatty acids (VLCFAs) perform pleiotropic roles in a wide range of biological processes, such as cell membrane formation, cell signal transduction, and endocrine regulation. Beef and milk are abundant of palmitic acid which can be further elongated into stearic acid for synthesizing VLCFAs. Elongase of very long chain fatty acid 6 (ELOVL6) is a rate-limiting enzyme for converting palmitic acid to stearic acid. Consequently, investigating the tissue expression patterns and transcriptional regulation of bovine ELOVL6 can provide new insights into improving the composition of beneficial fats in cattle and expanding the knowledge of transcriptional regulation mechanism among domestic animals. In the current study, we found that bovine ELOVL6 expressed ubiquitously. Dual-luciferase reporter assay identified that the core promoter region (-130/-41 bp) was located in the second CpG island. In addition, the deletion mutation of binding sites demonstrated that sterol regulatory element binding transcription factor 1 (SREBF1) and specific protein 1 (SP1) both were able to stimulate bovine ELOVL6 promoter activity independently, while resulting the similar effect. To confirm these findings, further RNA interference assays were executed in bovine mammary epithelial cells (BMECs). In summary, these data suggest that bovine ELOVL6 expressed ubiquitously and is activated by SREBF1 and SP1, via two binding sites present in the ELOVL6 promoter region between -130 bp to -41bp.

Fatty acid elongase7 is regulated via SP1 and is involved in lipid accumulation in bovine mammary epithelial cells

“…Moreover, the supply of ALA strengthen the binding of SP1 to the ELOVL7 proximal promoter, which leading to the accumulation of lipid droplets in bMECs. Our previous research discovered that SP1 bound at the promoter of bovine ELOVL6 to regulate its transcription (Chen, He, & Liu, ), which were proven to be the similar regulation pattern for the expression of ELOVL7 in the present study. These results illustrate that ELOVL7 appear to play an important role in lipogenesis, and extend our knowledge of bovine ELOVL7 in controlling lipid synthesis of mammary gland lipid in cattle, in addition, enlightening us the profound role of SP1 involving in the lipid metabolism.…”

“…Limited researches have indicated that ELOVL7 was activating by hormonal status, including insulin and androgen via sterol regulatory element binding transcription factor 1 (SREBF1) (Rodriguez‐Cruz, Sanchez Gonazalez, Sanchez Garcia, & Lopez‐Alarcon, ; Tamura et al, ). However, our previous research discovered that transcription factor Sp1 (SP1) bound at the promoter of ELOVL6 to regulate its transcription (Chen, He, & Liu, ), which enlightened us the similar regulation pattern for the expression of ELOVL7 .…”

Genome wide association study identifies SNPs associated with fatty acid composition in Chinese Wagyu cattle

“…Therefore, the role of ELOVL5 and ELOVL6 in the synthesis of FAs is of great importance for beef cattle breeding programs [24, 64, 65]. The investigation into the molecular mechanism of the ELOVL gene family can provide valuable insight into improving the composition of beneficial FA in cattle and expanding our knowledge of transcriptional regulation mechanisms in domestic animals [66].…”

The elongation of very long-chain fatty acid 6 gene product catalyses elongation ofn-13 : 0 andn-15 : 0 odd-chain SFA in human cells

“…ELOVL6 activity characterised by cloning of mammalian ELOVL6 ORF into expression vector and expressing the vector in mammalian cells shows that ELOVL6 specifically catalyses the elongation of ECSFA and MUFA with chain lengths of 12, 14 and 16 carbons (46,50) . ELOVL6 is found to be ubiquitously expressed in mice and bovine tissues (29,46) , and --------------------- --------------------- Human YLSYLVLFCHFFFEAYIGKMRK-TTKAE--265 Mouse YLSYLVLFCHFFFEAYIGKVKK-ATKAE--267 Rat YLSYLLLFCHFFFEAYIGKVKK-ATKAE--267 Monkey YLSYLVLFCHFFFEAYIGKMRK-TTKAE--265 Cattle YLSYFVLFCHFFFEAYIGSKMRKATKAD--264 Chicken YLSYFVLFCHFFFEAYIGKTTKARKVD---265 Frog YLSYFVLFCHFFFEAYITKTRKASKAD---265 Catfish YLSYFVLFCQFFFEAYINKTKSKNNAKKIQ 267 Zebrafish YLSYFVLFCQFFFEAYITKRKSNAAKKSQ-266 -------------I II III IV Fig. 1.…”