Identification The Mitochondrial Signal Sequence Of Marveld1and Study On The Interaction Relationship Between MARVELD1and Hsp70

MARVELD1， located on human chromosome10q24.2, encodes3238bp of mRNA.Our previous study found that MARVELD1was expressed in plenty of cell lines and wasdown-regulated in many tumor tissues. It has been predicted by bioinformatics that theN-terminal1-33amino acids of MARVELD1is a putative mitochondrial signal sequence.The result of colloidal gold immunoelectron microscopy suggested that MARVELD1expressed in mitochondria and nucleus. To understand the function of MARVELD1inmitochondria, the putative mitochondrial signal sequence and its roles in MARVELD1was studied.In this study, the full length and mitochondrial signal sequence-deleted truncate ofMARVELD1were stably transfected into A549cells, respectively. Usinginmunnofluorescence staining and western blotting analysis, we found that the cellstransfected with wide type (full length) of MARVELD1showed clear foci inmitochondria, while the mitochondrial localization of MARVELD1in cells transfectedwith mitochondrial signal sequence-deleted truncate of MARVELD1was reduced. Theresult suggested that the putative mitochondrial signal sequence may play part role toguide MARVELD1into mitochondria.In our previous study to screen the interactive protein of MARVELD1by GST-pulldown, Hsp70was found to be a potential binding protein of MARVELD1. Theinteraction between Hsp70and full length or truncated mutant of MARVELD1wereproved by using co-immunoprecipitation experiment. Although, MARVELD1was foundto be localized in mitochondria, the interaction between MARVELD1and mtHsp70(amitochondrial specific heat shock protein)could not be determined. However thepotential interaction between MARVELD1and MPP (a mitochondrial specific protein)was shown in co-immunoprecipitation experiment.