PMID- 20127721
OWN - NLM
STAT- MEDLINE
DCOM- 20100629
LR  - 20211203
IS  - 1097-4644 (Electronic)
IS  - 0730-2312 (Print)
IS  - 0730-2312 (Linking)
VI  - 109
IP  - 6
DP  - 2010 Apr 15
TI  - Alcohol and PRAS40 knockdown decrease mTOR activity and protein synthesis via 
      AMPK signaling and changes in mTORC1 interaction.
PG  - 1172-84
LID - 10.1002/jcb.22496 [doi]
AB  - The mTORC1 protein kinase complex consists of mTOR, raptor, mLST8/GbetaL and 
      PRAS40. Previously, we reported that mTOR plays an important role in regulating 
      protein synthesis in response to alcohol (EtOH). However, the mechanisms by which 
      EtOH regulates mTORC1 activity have not been established. Here, we investigated 
      the effect of EtOH on the phosphorylation and interaction of components of mTORC1 
      in C2C12 myocytes. We also examined the specific role that PRAS40 plays in this 
      process. Incubation of myocytes with EtOH (100 mM, 24 h) increased raptor and 
      PRAS40 phosphorylation. Likewise, there were increased levels of the PRAS40 
      upstream regulators Akt and IRS-1. EtOH also caused changes in mTORC1 
      protein-protein interactions. EtOH enhanced the binding of raptor and PRAS40 with 
      mTOR. These alterations occurred in concert with increased binding of 14-3-3 to 
      raptor, while the PRAS40 and 14-3-3 interaction was not affected. The shRNA 
      knockdown (KD) of PRAS40 decreased protein synthesis similarly to EtOH. PRAS40 KD 
      increased raptor phosphorylation and its association with 14-3-3, whereas 
      decreased GbetaL-mTOR binding. The effects of EtOH and PRAS40 KD were mediated by 
      AMPK. Both factors increased in vitro AMPK activity towards the substrate raptor. 
      In addition, KD enhanced the activity of AMPK towards TSC2. Collectively, our 
      results indicate that EtOH stabilizes the association of raptor, PRAS40, and 
      GbetaL with mTOR, while likewise increasing the interaction of raptor with 
      14-3-3. These data suggest a possible mechanism for the inhibitory effects of 
      EtOH on mTOR kinase activity and protein synthesis in myocytes.
FAU - Hong-Brown, Ly Q
AU  - Hong-Brown LQ
AD  - Department of Cellular and Molecular Physiology, Penn State College of Medicine, 
      500 University Drive, Hershey, PA 17033, USA. lqh10@psu.edu
FAU - Brown, C Randell
AU  - Brown CR
FAU - Kazi, Abid A
AU  - Kazi AA
FAU - Huber, Danuta S
AU  - Huber DS
FAU - Pruznak, Anne M
AU  - Pruznak AM
FAU - Lang, Charles H
AU  - Lang CH
LA  - eng
GR  - R01 AA011290/AA/NIAAA NIH HHS/United States
PT  - Journal Article
PL  - United States
TA  - J Cell Biochem
JT  - Journal of cellular biochemistry
JID - 8205768
RN  - 0 (Adaptor Proteins, Signal Transducing)
RN  - 0 (Carrier Proteins)
RN  - 0 (Intracellular Signaling Peptides and Proteins)
RN  - 0 (Multiprotein Complexes)
RN  - 0 (Phosphoproteins)
RN  - 0 (Proteins)
RN  - 0 (Regulatory-Associated Protein of mTOR)
RN  - 0 (Rptor protein, mouse)
RN  - 0 (Transcription Factors)
RN  - 0 (proline-rich Akt substrate, 40 kDa protein, mouse)
RN  - 3K9958V90M (Ethanol)
RN  - EC 2.7.1.1 (mTOR protein, mouse)
RN  - EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 1)
RN  - EC 2.7.11.1 (Protein Serine-Threonine Kinases)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
RN  - EC 2.7.11.31 (AMP-Activated Protein Kinases)
SB  - IM
MH  - AMP-Activated Protein Kinases/genetics/*metabolism
MH  - Adaptor Proteins, Signal Transducing
MH  - Animals
MH  - Carrier Proteins/metabolism
MH  - Cell Line
MH  - Ethanol/*pharmacology
MH  - Gene Expression Regulation/*drug effects
MH  - Immunoblotting
MH  - Immunoprecipitation
MH  - Intracellular Signaling Peptides and Proteins/*metabolism
MH  - Mechanistic Target of Rapamycin Complex 1
MH  - Mice
MH  - Multiprotein Complexes
MH  - Muscle Cells/drug effects/metabolism
MH  - Phosphoproteins/genetics/*metabolism
MH  - Phosphorylation/drug effects
MH  - Protein Binding/drug effects
MH  - Protein Serine-Threonine Kinases/*metabolism
MH  - Proteins
MH  - RNA Interference
MH  - Regulatory-Associated Protein of mTOR
MH  - *Signal Transduction/drug effects
MH  - TOR Serine-Threonine Kinases
MH  - Transcription Factors/genetics/*metabolism
PMC - PMC3657206
MID - NIHMS465063
EDAT- 2010/02/04 06:00
MHDA- 2010/06/30 06:00
PMCR- 2013/05/18
CRDT- 2010/02/04 06:00
PHST- 2010/02/04 06:00 [entrez]
PHST- 2010/02/04 06:00 [pubmed]
PHST- 2010/06/30 06:00 [medline]
PHST- 2013/05/18 00:00 [pmc-release]
AID - 10.1002/jcb.22496 [doi]
PST - ppublish
SO  - J Cell Biochem. 2010 Apr 15;109(6):1172-84. doi: 10.1002/jcb.22496.