PMID- 28592812
OWN - NLM
STAT- MEDLINE
DCOM- 20190109
LR  - 20211204
IS  - 2045-2322 (Electronic)
IS  - 2045-2322 (Linking)
VI  - 7
IP  - 1
DP  - 2017 Jun 7
TI  - Activity-independent targeting of mTOR to lysosomes in primary osteoclasts.
PG  - 3005
LID - 10.1038/s41598-017-03494-2 [doi]
LID - 3005
AB  - Mammalian target of rapamycin (mTOR) is activated by numerous stimuli, including 
      amino acids and growth factors. This kinase is part of the mTOR complex 1 
      (mTORC1) which regulates cell proliferation, differentiation, and autophagy. 
      Active mTORC1 is located on lysosomes and has been reported to disassociate from 
      the lysosomal surface in the absence of amino acids. Furthermore, mTORC1 activity 
      has been linked to the vacuolar H(+)-ATPases (V-ATPases), the proton pumps 
      responsible for lysosomal acidification; however, the exact role of the V-ATPases 
      in mTORC1 signaling is not known. To elucidate the mechanisms involved in mTORC1 
      regulation by the V-ATPases, we used primary osteoclasts derived from mice 
      carrying a point (R740S) mutation in the a3 subunit of the V-ATPase. In these 
      cells, the mutant protein is expressed but the pump is not functional, resulting 
      in higher lysosomal pH. By analyzing mTOR activation, mTOR/lysosome 
      co-localization, and lysosomal positioning using confocal microscopy, 
      fractionation, and ultrapure lysosomal purification methods, we demonstrate that 
      in primary osteoclasts, mTOR is localized on the lysosomal surface even when mTOR 
      activity is inhibited. Our findings reveal that mTOR targeting to the lysosome in 
      osteoclasts is activity-independent, and that its disassociation from the 
      lysosome during starvation is not universal.
FAU - Wang, Andrew
AU  - Wang A
AD  - Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
FAU - Carraro-Lacroix, Luciene R
AU  - Carraro-Lacroix LR
AD  - Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
FAU - Owen, Celeste
AU  - Owen C
AD  - Centre for Modeling Human Disease, Samuel Lunenfeld-Tanenbaum Research Institute, 
      Mount Sinai Hospital, Toronto, ON, Canada.
FAU - Gao, Bowen
AU  - Gao B
AD  - Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada.
FAU - Corey, Paul N
AU  - Corey PN
AD  - Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada.
FAU - Tyrrell, Pascal
AU  - Tyrrell P
AD  - Department of Statistical Sciences, University of Toronto, Toronto, ON, Canada.
AD  - Department of Medical Imaging, University of Toronto, Toronto, ON, Canada.
FAU - Brumell, John H
AU  - Brumell JH
AD  - Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.
AD  - Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
AD  - Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
FAU - Voronov, Irina
AU  - Voronov I
AUID- ORCID: 0000-0003-2369-3324
AD  - Faculty of Dentistry, University of Toronto, Toronto, ON, Canada. 
      irina.voronov@utoronto.ca.
LA  - eng
GR  - ONM-143056/CIHR/Canada
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20170607
PL  - England
TA  - Sci Rep
JT  - Scientific reports
JID - 101563288
RN  - 0 (Mutant Proteins)
RN  - EC 2.7.1.1 (mTOR protein, mouse)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - EC 3.6.1.- (Vacuolar Proton-Translocating ATPases)
SB  - IM
MH  - Animals
MH  - Cell Fractionation
MH  - Cells, Cultured
MH  - Lysosomes/*metabolism
MH  - Mice
MH  - Microscopy, Confocal
MH  - Mutant Proteins/metabolism
MH  - Osteoclasts/*metabolism
MH  - Protein Transport
MH  - TOR Serine-Threonine Kinases/*metabolism
MH  - Vacuolar Proton-Translocating ATPases/genetics/metabolism
PMC - PMC5462732
COIS- The authors declare that they have no competing interests.
EDAT- 2017/06/09 06:00
MHDA- 2019/01/10 06:00
PMCR- 2017/06/07
CRDT- 2017/06/09 06:00
PHST- 2017/01/04 00:00 [received]
PHST- 2017/04/28 00:00 [accepted]
PHST- 2017/06/09 06:00 [entrez]
PHST- 2017/06/09 06:00 [pubmed]
PHST- 2019/01/10 06:00 [medline]
PHST- 2017/06/07 00:00 [pmc-release]
AID - 10.1038/s41598-017-03494-2 [pii]
AID - 3494 [pii]
AID - 10.1038/s41598-017-03494-2 [doi]
PST - epublish
SO  - Sci Rep. 2017 Jun 7;7(1):3005. doi: 10.1038/s41598-017-03494-2.