Proteome differences between brown and white fat mitochondria reveal specialized metabolic functions.
Mitochondria are functionally specialized in different tissues, and a detailed understanding of this specialization is important to elucidate mitochondrial involvement in normal physiology and disease. In adaptive thermogenesis, brown fat converts mitochondrial energy to heat, whereas tissue-specific functions of mitochondria in white fat are less characterized. Here we apply high-resolution quantitative mass spectrometry to directly and accurately compare the in vivo mouse mitochondrial proteomes of brown and white adipocytes. Their proteomes are substantially different qualitatively and quantitatively and are furthermore characterized by tissue-specific protein isoforms, which are modulated by cold exposure. At transcript and proteome levels, brown fat mitochondria are more similar to their counterparts in muscle. Conversely, white fat mitochondria not only selectively express proteins that support anabolic functions but also degrade xenobiotics, revealing a protective function of this tissue. In vivo comparison of organellar proteomes can thus directly address functional questions in metabolism.
Forner
Francesca
F
Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, 82152 Martinsried, Germany.
Kumar
Chanchal
C
Luber
Christian A
CA
Fromme
Tobias
T
Klingenspor
Martin
M
Mann
Matthias
M
D041721:3T3-L1 Cells; D002001:Adipose Tissue, Brown / Q000166:cytology* / Q000378:metabolism; D052436:Adipose Tissue, White / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002952:Citric Acid Cycle / Q000502:physiology; D003080:Cold Temperature; D004734:Energy Metabolism; D005227:Fatty Acids / Q000378:metabolism; D020869:Gene Expression Profiling; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000737:chemistry* / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000032:analysis*; D010085:Oxidative Phosphorylation; D040081:Protein Array Analysis; D020543:Proteome / Q000032:analysis*
D005227:Fatty Acids; D024101:Mitochondrial Proteins; D020543:Proteome