Profiling phosphoproteins of yeast mitochondria reveals a role of phosphorylation in assembly of the ATP synthase.
Mitochondria are crucial for numerous cellular processes, yet the regulation of mitochondrial functions is only understood in part. Recent studies indicated that the number of mitochondrial phosphoproteins is higher than expected; however, the effect of reversible phosphorylation on mitochondrial structure and function has only been defined in a few cases. It is thus crucial to determine authentic protein phosphorylation sites from highly purified mitochondria in a genetically tractable organism. The yeast Saccharomyces cerevisiae is a major model organism for the analysis of mitochondrial functions. We isolated highly pure yeast mitochondria and performed a systematic analysis of phosphorylation sites by a combination of different enrichment strategies and mass spectrometry. We identified 80 phosphorylation sites in 48 different proteins. These mitochondrial phosphoproteins are involved in critical mitochondrial functions, including energy metabolism, protein biogenesis, fatty acid metabolism, metabolite transport, and redox regulation. By combining yeast genetics and in vitro biochemical analysis, we found that phosphorylation of a serine residue in subunit g (Atp20) regulates dimerization of the mitochondrial ATP synthase. The authentic phosphoproteome of yeast mitochondria will represent a rich source to uncover novel roles of reversible protein phosphorylation.
Reinders
Jörg
J
Rudolf Virchow Center/Deutsche Forschungsgemeinschaft Research Center for Experimental Biomedicine, Universität Würzburg, D-97078 Würzburg, Germany.
Wagner
Karina
K
Zahedi
Rene P
RP
Stojanovski
Diana
D
Eyrich
Beate
B
van der Laan
Martin
M
Rehling
Peter
P
Sickmann
Albert
A
Pfanner
Nikolaus
N
Meisinger
Chris
C
D000595:Amino Acid Sequence; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000032:analysis* / Q000145:classification / Q000378:metabolism; D025261:Mitochondrial Proton-Translocating ATPases / Q000378:metabolism*; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000032:analysis* / Q000145:classification / Q000378:metabolism; D010766:Phosphorylation; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis* / Q000145:classification / Q000378:metabolism
D024101:Mitochondrial Proteins; D010750:Phosphoproteins; D029701:Saccharomyces cerevisiae Proteins; D025261:Mitochondrial Proton-Translocating ATPases