TY - JOUR
T1 - CREB-1α is recruited to and mediates upregulation of the cytochrome c promoter during enhanced mitochondrial biogenesis accompanying skeletal muscle differentiation
AU - Franko, Andras
AU - Mayer, Sabine
AU - Thiel, Gerald
AU - Mercy, Ludovic
AU - Arnould, Thierry
AU - Hornig-Do, Hue Tran
AU - Wiesner, Rudolf J.
AU - Goffart, Steffi
N1 - Publication code : RES. ACAD.
PY - 2008/4
Y1 - 2008/4
N2 - To further understand pathways coordinating the expression of nuclear genes encoding mitochondrial proteins, we studied mitochondrial biogenesis during differentiation of myoblasts to myotubes. This energy-demanding process was accompanied by a fivefold increase of ATP turnover, covered by an eightfold increase of mitochondrial activity. While no change in mitochondrial DNA copy number was observed, mRNAs as well as proteins for nucleus-encoded cytochrome c, cytochrome c oxidase subunit IV, and mitochondrial transcription factor A (TFAM) increased, together with total cellular RNA and protein levels. Detailed analysis of the cytochrome c promoter by luciferase reporter, binding affinity, and electrophoretic mobility shift assays as well as mutagenesis studies revealed a critical role for cyclic AMP responsive element binding protein 1 (CREB-I) for promoter activation. Expression of two CREB-1 isoforms was observed by using specific antibodies and quantitative reverse transcription-PCR, and a shift from phosphorylated CREB-1Δ in myoblasts to phosphorylated CREB-1α protein in myotubes was shown, while mRNA ratios remained unchanged. Chromatin immunoprecipitation assays confirmed preferential binding of CREB-1α in situ to the cytochrome c promoter in myotubes. Overexpression of constitutively active and dominant-negative forms supported the key role of CREB-1 in regulating the expression of genes encoding mitochondrial proteins during myogenesis and probably also in other situations of enhanced mitochondrial biogenesis. Copyright © 2008, American Society for Microbiology. All Rights Reserved.
AB - To further understand pathways coordinating the expression of nuclear genes encoding mitochondrial proteins, we studied mitochondrial biogenesis during differentiation of myoblasts to myotubes. This energy-demanding process was accompanied by a fivefold increase of ATP turnover, covered by an eightfold increase of mitochondrial activity. While no change in mitochondrial DNA copy number was observed, mRNAs as well as proteins for nucleus-encoded cytochrome c, cytochrome c oxidase subunit IV, and mitochondrial transcription factor A (TFAM) increased, together with total cellular RNA and protein levels. Detailed analysis of the cytochrome c promoter by luciferase reporter, binding affinity, and electrophoretic mobility shift assays as well as mutagenesis studies revealed a critical role for cyclic AMP responsive element binding protein 1 (CREB-I) for promoter activation. Expression of two CREB-1 isoforms was observed by using specific antibodies and quantitative reverse transcription-PCR, and a shift from phosphorylated CREB-1Δ in myoblasts to phosphorylated CREB-1α protein in myotubes was shown, while mRNA ratios remained unchanged. Chromatin immunoprecipitation assays confirmed preferential binding of CREB-1α in situ to the cytochrome c promoter in myotubes. Overexpression of constitutively active and dominant-negative forms supported the key role of CREB-1 in regulating the expression of genes encoding mitochondrial proteins during myogenesis and probably also in other situations of enhanced mitochondrial biogenesis. Copyright © 2008, American Society for Microbiology. All Rights Reserved.
UR - http://www.scopus.com/inward/record.url?scp=41149090096&partnerID=8YFLogxK
U2 - 10.1128/MCB.00980-07
DO - 10.1128/MCB.00980-07
M3 - Article
C2 - 18227154
SN - 0270-7306
VL - 28
SP - 2446
EP - 2459
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
IS - 7
ER -