Effects of proline on mTORC1 signaling pathway in pTr2 cells. (A) The protein abundance of total and p-mTORC1 in pTr2 cells. (B) The protein abundance of total and p-p70S6K in pTr2 cells. (C) The protein abundance of total and p-S6 in pTr2 cells. (D) The protein abundance of total and p-4E-BP1 in pTr2 cells. Data are expressed as the percentage of control group. Values are means ± SEMs, n = 3. Means at a time point without a common letter differ, p < 0.05. 4E-BP1, eukaryotic translation initiation factor 4E-binding protein 1; mTORC1, mammalian target of rapamycin complex 1; p, phosphorylated; p70S6K, ribosomal protein S6 kinase; pTr2, porcine trophectoderm cell line 2.