[DNA polymerase delta-interacting protein 1 enhances GFP protein degradation]
Bo Zhang1, Fangliang Zhou2, Fangguo Lu2
1School of Medicine, Hunan University of Chinese Medicine, Changsha 410208; Key Laboratory of Protein Chemistry and Developmental Biology, Ministry of Education, School of Life Sciences, Hunan Normal University, Changsha 410081, China.
Objective:
To prove whether the over-expression of DNA polymerase delta-interacting protein 1 (PDIP1) protein can promote the degradation of exogenous GFP protein.
Methods:
The plasmids of pEGFP-C3 and pCMV-myc-PDIP1 were co-transfected into HEK293 cells. The fluorescence intensity of the transfected cells was analyzed using fluorescence microscope. The expressions of GFP and PDIP1 were measured by Western blotting. Then, the expressions of GFP and PDIP1 were again detected in the cells which were treated by ammonium chloride or MG132, respectively.
Results:
Compared with the ones transfected with pEGFP-C3 along, green fluorescence intensity of HEK293 cells transfected with the plasmids of pEGFP-C3 and pCMV-myc-PDIP1 was lower, and GFP level decreased as the expression of PDIP1 increased. The decreased GFP was significantly alleviated by the proteasome inhibitor MG132 treatment, but was not significantly affected by ammonium chloride.
Conclusion:
Over-expression of PDIP1 can promote the degradation of exogenous GFP, and the degradation might be caused via proteasome pathway. Our results suggest that PDIP1 might have a hand in the degradation of some proteins in cells.
