A new face on apoptosis: death-associated protein 3 and PDCD9 are mitochondrial ribosomal proteins.
Two proteins known to be involved in promoting apoptosis in mammalian cells have been identified as components of the mammalian mitochondrial ribosome. Proteolytic digestion of whole mitochondrial ribosomal subunits followed by analysis of the peptides present using liquid chromatography-tandem mass spectrometry revealed that the proapoptotic proteins, death-associated protein 3 (DAP3) and the programmed cell death protein 9, are both components of the mitochondrial ribosome. DAP3 has motifs characteristic of guanine nucleotide binding proteins and is probably the protein that accounts for the nucleotide binding activity of mammalian mitochondrial ribosomes. The observations reported here implicate mitochondrial protein synthesis as a major component in cellular apoptotic signaling pathways.
Cavdar Koc
E
E
Department of Chemistry, University of North Carolina, Chapel Hill, 27599-3290, USA.
Ranasinghe
A
A
Burkhart
W
W
Blackburn
K
K
Koc
H
H
Moseley
A
A
Spremulli
L L
LL
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D002417:Cattle; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D013058:Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism* / Q000502:physiology; D008969:Molecular Sequence Data; D017368:Protein Prenylation; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D051017:Apoptosis Regulatory Proteins; D018797:Cell Cycle Proteins; C097041:DAP3 protein, human; D011506:Proteins; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C111664:protein p52, mammalian