PMID- 20464060
OWN - NLM
STAT- MEDLINE
DCOM- 20101222
LR  - 20211020
IS  - 1528-3658 (Electronic)
IS  - 1076-1551 (Print)
IS  - 1076-1551 (Linking)
VI  - 16
IP  - 9-10
DP  - 2010 Sep-Oct
TI  - PRAS40 regulates protein synthesis and cell cycle in C2C12 myoblasts.
PG  - 359-71
LID - 10.2119/molmed.2009.00168 [doi]
AB  - PRAS40 is an mTOR binding protein that has complex effects on cell metabolism. 
      Our study tests the hypothesis that PRAS40 knockdown (KD) in C2C12 myocytes will 
      increase protein synthesis via upregulation of the mTOR-S6K1 pathway. PRAS40 KD 
      was achieved using lentiviruses to deliver short hairpin (sh)-RNA targeting 
      PRAS40 or a scrambled control. C2C12 cells were used as either myoblasts or 
      differentiated to myotubes. Knockdown reduced PRAS40 mRNA and protein content by 
      >80% of time-matched control values but did not alter the phosphorylation of mTOR 
      substrates, 4E-BP1 or S6K1, in neither myoblasts nor myotubes. No change in 
      protein synthesis in myotubes was detected, as measured by the incorporation of 
      (35)S-methionine. In contrast, protein synthesis was reduced 25% in myoblasts. 
      PRAS40 KD in myoblasts also decreased proliferation rate with an increased 
      percent of cells retained in the G1 phase. PRAS40 KD myoblasts were larger in 
      diameter and had a decreased rate of myotube formation as assessed by myosin 
      heavy chain content. Immunoblotting revealed a 25-30% decrease in total p21 and 
      S807/811 phosphorylated Rb protein considered critical for G1 to S phase 
      progression. Reduction in protein synthesis was not due to increased apoptosis, 
      since cleaved caspase-3 and DNA laddering did not differ between groups. In 
      contrast, the protein content of LC3B-II was decreased by 30% in the PRAS40 KD 
      myoblasts, suggesting a decreased rate of autophagy. Our results suggest that a 
      reduction in PRAS40 specifically impairs myoblast protein synthesis, cell cycle, 
      proliferation and differentiation to myotubes.
FAU - Kazi, Abid A
AU  - Kazi AA
AD  - Department of Cellular and Molecular Physiology, Pennsylvania State University 
      College of Medicine, Hershey, PA 17033, USA. akazi@hmc.psu.edu
FAU - Lang, Charles H
AU  - Lang CH
LA  - eng
GR  - GM38032/GM/NIGMS NIH HHS/United States
GR  - R01 AA011290/AA/NIAAA NIH HHS/United States
GR  - R37 AA011290/AA/NIAAA NIH HHS/United States
GR  - AA11290/AA/NIAAA NIH HHS/United States
GR  - R01 GM038032/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20100505
PL  - England
TA  - Mol Med
JT  - Molecular medicine (Cambridge, Mass.)
JID - 9501023
RN  - 0 (Phosphoproteins)
RN  - 0 (RNA, Small Interfering)
RN  - 0 (Ribonucleotides)
RN  - 0 (proline-rich Akt substrate, 40 kDa protein, mouse)
RN  - 360-97-4 (Aminoimidazole Carboxamide)
RN  - 67763-96-6 (Insulin-Like Growth Factor I)
RN  - EC 3.6.4.1 (Myosin Heavy Chains)
RN  - F0X88YW0YK (AICA ribonucleotide)
SB  - IM
MH  - Aminoimidazole Carboxamide/analogs & derivatives/pharmacology
MH  - Animals
MH  - Apoptosis/drug effects
MH  - Autophagy/drug effects
MH  - *Cell Cycle/drug effects
MH  - Cell Differentiation/drug effects
MH  - Cell Proliferation/drug effects
MH  - Cell Size/drug effects
MH  - Gene Knockdown Techniques
MH  - Insulin-Like Growth Factor I/pharmacology
MH  - Mice
MH  - Muscle Development/drug effects
MH  - Muscle Fibers, Skeletal/cytology/drug effects/metabolism
MH  - Myoblasts/*cytology/drug effects/*metabolism
MH  - Myosin Heavy Chains/metabolism
MH  - Phosphoproteins/*metabolism
MH  - *Protein Biosynthesis/drug effects
MH  - RNA, Small Interfering/metabolism
MH  - Ribonucleotides/pharmacology
PMC - PMC2935957
EDAT- 2010/05/14 06:00
MHDA- 2010/12/24 06:00
PMCR- 2010/09/01
CRDT- 2010/05/14 06:00
PHST- 2009/11/13 00:00 [received]
PHST- 2010/05/04 00:00 [accepted]
PHST- 2010/05/14 06:00 [entrez]
PHST- 2010/05/14 06:00 [pubmed]
PHST- 2010/12/24 06:00 [medline]
PHST- 2010/09/01 00:00 [pmc-release]
AID - molmed.2009.00168 [pii]
AID - 09_168_kazi [pii]
AID - 10.2119/molmed.2009.00168 [doi]
PST - ppublish
SO  - Mol Med. 2010 Sep-Oct;16(9-10):359-71. doi: 10.2119/molmed.2009.00168. Epub 2010 
      May 5.