TY - JOUR
T1 - CCP1/Nna1 functions in protein turnover in mouse brain
T2 - Implications for cell death in Purkinje cell degeneration mice
AU - Berezniuk, Iryna
AU - Sironi, Juan
AU - Callaway, Myrasol B.
AU - Castro, Leandro M.
AU - Hirata, Izaura Y.
AU - Ferro, Emer S.
AU - Fricker, Lloyd D.
PY - 2010/6
Y1 - 2010/6
N2 - Purkinje cell degeneration (pcd) mice have a mutation within the gene encoding cytosolic carboxypeptidase 1 (CCP1/Nna1), which has homology to metallocarboxypeptidases. To assess the function of CCP1/Nna1, quantitative proteomics and peptidomics approaches were used to compare proteins and peptides in mutant and wild-type mice. Hundreds of peptides derived from cytosolic and mitochondrial proteins are greatly elevated in pcd mouse hypothalamus, amygdala, cortex, prefrontal cortex, and striatum. However, the major proteins detected on 2-D gel electrophoresis were present in mutant and wild-type mouse cortex and hypothalamus at comparable levels, and proteasome activity is normal in these brain regions of pcd mice, suggesting that the increase in cellular peptide levels in the pcd mice is due to reduced degradation of the peptides downstream of the proteasome. Both nondegenerating and degenerating regions of pcd mouse brain, but not wild-type mouse brain, show elevated autophagy, which can be triggered by a decrease in amino acid levels. Taken together with previous studies on CCP1/Nna1, these data suggest that CCP1/Nna1 plays a role in protein turnover by cleaving proteasome-generated peptides into amino acids and that decreased peptide turnover in the pcd mice leads to cell death.
AB - Purkinje cell degeneration (pcd) mice have a mutation within the gene encoding cytosolic carboxypeptidase 1 (CCP1/Nna1), which has homology to metallocarboxypeptidases. To assess the function of CCP1/Nna1, quantitative proteomics and peptidomics approaches were used to compare proteins and peptides in mutant and wild-type mice. Hundreds of peptides derived from cytosolic and mitochondrial proteins are greatly elevated in pcd mouse hypothalamus, amygdala, cortex, prefrontal cortex, and striatum. However, the major proteins detected on 2-D gel electrophoresis were present in mutant and wild-type mouse cortex and hypothalamus at comparable levels, and proteasome activity is normal in these brain regions of pcd mice, suggesting that the increase in cellular peptide levels in the pcd mice is due to reduced degradation of the peptides downstream of the proteasome. Both nondegenerating and degenerating regions of pcd mouse brain, but not wild-type mouse brain, show elevated autophagy, which can be triggered by a decrease in amino acid levels. Taken together with previous studies on CCP1/Nna1, these data suggest that CCP1/Nna1 plays a role in protein turnover by cleaving proteasome-generated peptides into amino acids and that decreased peptide turnover in the pcd mice leads to cell death.
KW - Aminopeptidase
KW - Carboxypeptidase
KW - Neurodegeneration
KW - Proteasome
KW - Protein degradation
UR - http://www.scopus.com/inward/record.url?scp=77953495946&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77953495946&partnerID=8YFLogxK
U2 - 10.1096/fj.09-147942
DO - 10.1096/fj.09-147942
M3 - Article
C2 - 20061535
AN - SCOPUS:77953495946
SN - 0892-6638
VL - 24
SP - 1813
EP - 1823
JO - FASEB Journal
JF - FASEB Journal
IS - 6
ER -