Identification of a subunit of NADH-dehydrogenase as a p49/STRAP-binding protein
1 From the Donald W. Reynolds Department of Geriatrics, The University of Arkansas for Medical Sciences and Geriatric Research, Education, and Clinical Center, Little Rock, AR, USA
2 Central Arkansas Veterans Healthcare System, Geriatric and Extended Care, Little Rock, AR, USA
3 Central Arkansas Veterans Healthcare System, Little Rock, AR, USA
BMC Cell Biology 2008, 9:8 doi:10.1186/1471-2121-9-8Published: 29 January 2008
The p49/STRAP (or SRFBP1) protein was recently identified in our laboratory as a cofactor of serum response factor that contributes to the regulation of SRF target genes in the heart.
In the present study, we report that NDUFAB1, a nuclear encoded subunit of NADH dehydrogenase, represented the majority of the cDNA clones that interacted with p49/STRAP in multiple screenings using the yeast two-hybrid system. The p49/STRAP and NDUFAB1 proteins interacted and co-localized with each other in the cell. The p49/STRAP protein contains four classic nuclear localization sequence motifs, and it was observed to be present predominantly in the nucleus. Overexpression of p49/STRAP altered the intracellular level of NAD, and reduced the NAD/NADH ratio. Overexpression of p49/STRAP also induced the deacetylation of serum response factor.
These data suggest that p49/STRAP plays a role in the regulation of intracellular processes such as cardiac cellular metabolism, gene expression, and possibly aging.