Enhanced mitochondrial degradation of yeast cytochrome c with amphipathic structures.
The dispensable N-terminus of iso-1-cytochrome c (iso-1) in the yeast Saccharomyces cerevisiae was replaced by 11 different amphipathic structures. Rapid degradation of the corresponding iso-1 occurred, with the degree of degradation increasing with the amphipathic moments; and this amphipathic-dependent degradation was designated ADD. ADD occurred with the holo-forms in the mitochondria but not as the apo-forms in the cytosol. The extreme mutant type degraded with a half-life of approximately 12 min, whereas the normal iso-1 was stable over hours. ADD was influenced by the rho+/rho- state and by numerous chromosomal genes. Most importantly, ADD appeared to be specifically suppressed to various extents by deletions of any of the YME1, AFG3, or RCA1 genes encoding membrane-associated mitochondrial proteases, probably because the amphipathic structures caused a stronger association with the mitochondrial inner membrane and its associated proteases. The use of ADD assisted in the differentiation of substrates of different mitochondrial degradation pathways.
Chen
Xi
X
Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA.
Moerschell
Richard P
RP
Pearce
David A
DA
Ramanan
Durga D
DD
Sherman
Fred
F
D000595:Amino Acid Sequence; D001483:Base Sequence; D045304:Cytochromes c / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D008928:Mitochondria / Q000378:metabolism*; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D009626:Terminology as Topic
D012333:RNA, Messenger; D045304:Cytochromes c