[The functional and pathological analysis of mitochondrial protein p32].

p32 is an evolutionarily conserved and ubiquitously expressed multifunctional protein. Although p32 exists at diverse intra and extracellular sites, it is predominantly localized to the mitochondrial matrix near the nucleoid associated with mitochondrial transcription factor A. p32-deficient mice exhibited mid-gestation lethality associated with a severe developmental defect of the embryo. Primary embryonic fibroblasts isolated from p32-knockout embryos showed severe dysfunction of the mitochondrial respiratory chain because of severely impaired mitochondrial protein synthesis. The RNA-binding ability of p32 is well correlated with mitochondrial translation. We also found that p32 is highly expressed in prostate tumor samples and its expression is significantly associated with the Gleason score, pathologic stage, and relapse. These data suggest that p32 is critical for prostate cancer cell proliferation and may be a novel marker of clinical progression in prostate cancer.