Similar intracellular peptide profile of TAP1/β2 microglobulin double-knockout mice and C57BL/6 wild-type mice as revealed by peptidomic analysis.
Cells produce and use peptides in distinctive ways. In the present report, using isotope labeling plus semi-quantitative mass spectrometry, we evaluated the intracellular peptide profile of TAP1/β2m⁻(/)⁻ (transporter associated with antigen-processing 1/ß2 microglobulin) double-knockout mice and compared it with that of C57BL/6 wild-type animals. Overall, 92 distinctive peptides were identified, and most were shown to have a similar concentration in both mouse strains. However, some peptides showed a modest increase or decrease (~2-fold), whereas a glycine-rich peptide derived from the C-terminal of neurogranin (KGPGPGGPGGAGGARGGAGGGPSGD) showed a substantial increase (6-fold) in TAP1/β2m⁻(/)⁻ mice. Thus, TAP1 and β2microglobulin have a small influence on the peptide profile of neuronal tissue, suggesting that the presence of peptides derived from intracellular proteins in neuronal tissue is not associated with antigens of the class I major histocompatibility complex. Therefore, it is possible that these intracellular peptides play a physiological role.
Castro
Leandro M
LM
Department of Cell Biology and Development, Biomedical Science Institute, São Paulo, SP, Brazil.
Berti
Denise A
DA
Russo
Lilian C
LC
Coelho
Verônica
V
Gozzo
Fábio C
FC
Oliveira
Vitor
V
Ferro
Emer S
ES
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D040901:Proteomics; D053719:Tandem Mass Spectrometry; D001613:beta 2-Microglobulin / Q000737:chemistry* / Q000235:genetics
D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D018528:ATP-Binding Cassette Transporters; D010455:Peptides; C486171:Tap1 protein, mouse; D001613:beta 2-Microglobulin