The mucolipidosis IV Ca2+ channel TRPML1 (MCOLN1) is regulated by the TOR kinase.
Bottom Line: In the present study, we provide evidence that the target of rapamycin (TOR), a nutrient-sensitive protein kinase that negatively regulates autophagy, directly targets and inactivates the TRPML1 channel and thereby functional autophagy, through phosphorylation.Further, mutating these phosphorylation sites to unphosphorylatable residues proved to block TOR regulation of the TRPML1 channel.These findings suggest a mechanism for how TOR activity may regulate the TRPML1 channel.
Affiliation: Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, NC 27707, U.S.A. firstname.lastname@example.org).Show MeSH
Related in: MedlinePlus
Mentions: To determine whether TOR could directly phosphorylate TRPML1 in vitro, kinase assays were performed to monitor the incorporation of 32P into modified versions of the TRPML1 C-terminal peptide (refer to the ‘Experimental’ for the exact sequences of these peptides; Figures 1A, 5A and 5B; Supplementary Figure S6) [42,43]. In brief, either Ser572 or Ser576 (or both) was replaced with an unphosphorylatable alanine residue in the C-terminal TRPML1 peptide for the 32P incorporation assays. The kinase assays revealed that the C-terminal peptide is indeed a robust TOR substrate (Figures 5A and 5B), whereas versions of the peptide altered at one or both of the putative serine residues (S572A/S576A) were relatively poor TOR substrates (Supplementary Figure S6).
Affiliation: Biomanufacturing Research Institute and Technology Enterprise (BRITE), North Carolina Central University, Durham, NC 27707, U.S.A. email@example.com).