Affordable Access

deepdyve-link
Publisher Website

Methionine Induces LAT1 Expression in Dairy Cow Mammary Gland by Activating the mTORC1 Signaling Pathway.

Authors
  • Duan, Xiaoyu1
  • Lin, Ye1, 2
  • Lv, He1
  • Yang, Yang1
  • Jiao, Hongtao1
  • Hou, Xiaoming1, 3
  • 1 1 College of Life Science, Northeast Agricultural University , Harbin, China . , (China)
  • 2 2 Key Laboratory of Dairy Science of Education Ministry, Northeast Agricultural University , Harbin, China . , (China)
  • 3 3 Key Laboratory of Animal Cellular and Genetics Engineering of Heilongjiang Province, Northeast Agricultural University , Harbin, China . , (China)
Type
Published Article
Journal
DNA and Cell Biology
Publisher
Mary Ann Liebert
Publication Date
Dec 01, 2017
Volume
36
Issue
12
Pages
1126–1133
Identifiers
DOI: 10.1089/dna.2017.3792
PMID: 29040000
Source
Medline
Keywords
License
Unknown

Abstract

Methionine is the limiting amino acid for milk protein synthesis in dairy cows. The effect of methionine availability on milk protein synthesis is dependent on its active transport into cells through amino acid transporters. L-type amino acid transporter 1 (LAT1), which induces the transport of neutral amino acids, is highly expressed in lactating mammary gland. However, the effect of methionine on LAT1 expression and the mechanism governing this process in dairy cow mammary gland are poorly understood. In this study, we show that treatment of dairy cow mammary epithelial cells with increasing concentrations of methionine for 24 h resulted in increased expression of LAT1 and its associated protein 4F2 heavy chain (4F2hc). Maximal expression levels occurred after treatment with 0.6 mM methionine. Methionine treatment also increased cell viability and β-casein synthesis. Western blots showed that methionine induced LAT1 and 4F2hc expression by activating mammalian target of rapamycin complex 1 (mTORC1) signaling. Inhibition of mTORC1 signaling by rapamycin or raptor siRNA prevented the upregulation of LAT1 and 4F2hc. These results indicate that methionine may activate the mTORC1 signaling pathway and further increase LAT1 and 4F2hc expression in dairy cow mammary gland, thus affecting milk protein synthesis.

Report this publication

Statistics

Seen <100 times