Open Accessp32/gC1qR is indispensable for fetal development and mitochondrial translation: importance of its RNA-binding ability
Author(s) -
Minoru Yagi,
Takeshi Uchiumi,
Shinya Takazaki,
Bungo Okuno,
Masatoshi Nomura,
Shin Ichi Yoshida,
Tomotake Kanki,
Dongchon Kang
Publication year - 2012
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/gks774
Subject(s) - biology , mitochondrion , microbiology and biotechnology , rna , mitochondrial dna , messenger rna , translation (biology) , nucleoid , immunoprecipitation , rna binding protein , gene , genetics , escherichia coli
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. Nonetheless, its function in the matrix is poorly understood. Here, we determined p32 function via generation of p32-knockout mice. 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. Recombinant p32 binds RNA, not DNA, and endogenous p32 interacts with all mitochondrial messenger RNA species in vivo. The RNA-binding ability of p32 is well correlated with the mitochondrial translation. Co-immunoprecipitation revealed the close association of p32 with the mitoribosome. We propose that p32 is required for functional mitoribosome formation to synthesize proteins within mitochondria.