INVESTIGADORES
HALLAK Marta Elena
artículos
Título:
Post-translational arginylation of calreticulin: a new isospecies of calreticulin component of stress granules.
Autor/es:
M. B. DECCA, M. A. CARPIO, C. BOSC, M. R. GALIANO, D. JOB, A. ANDRIEUX AND M. E. HALLAK
Revista:
Journal Biological Chemistry
Editorial:
American Society for Biochemistry and Molecular Biology
Referencias:
Año: 2007 vol. 282 p. 8237 - 8241
ISSN:
0021-9258
Resumen:
Post-translational arginylation consists of the covalent union
of an arginine residue to a Glu, Asp, or Cys amino acid at the
N-terminal position of proteins. This reaction is catalyzed by the
enzyme arginyl-tRNA protein transferase. Using mass spectrometry,
we have recently demonstrated in vitro the post-translational
incorporation of arginine into the calcium-binding protein
calreticulin (CRT). To further study arginylated CRT we
raised an antibody against the peptide (RDPAIYFK) that contains
an arginine followed by the first 7 N-terminal amino acids
of mature rat CRT. This antibody specifically recognizes CRT
obtained from rat soluble fraction that was arginylated in vitro
in vitro the post-translational
incorporation of arginine into the calcium-binding protein
calreticulin (CRT). To further study arginylated CRT we
raised an antibody against the peptide (RDPAIYFK) that contains
an arginine followed by the first 7 N-terminal amino acids
of mature rat CRT. This antibody specifically recognizes CRT
obtained from rat soluble fraction that was arginylated in vitroin vitro
and also recognizes endogenous arginylatedCRTfrom NIH 3T3
cells in culture, indicating that CRT arginylation takes place in
living cells. Using this antibody we found that arginylation of
CRT is Ca2-regulated. In vitro and in NIH 3T3 cells in culture,
the level of arginylated CRT increased with the addition of a
Ca2 chelator to the medium, whereas a decreased arginine
incorporation into CRT was found in the presence of Ca2. The
arginylated CRT was observed in the cytosol, in contrast to the
non-arginylated CRT that is in the endoplasmic reticulum.
Under stress conditions, arginylated CRT was found associated
to stress granules. These results suggest that CRT arginylation
occurs in the cytosolic pool of mature CRT (defined by an Asp
acid N-terminal) that is probably retrotranslocated from the
endoplasmic reticulum.
2-regulated. In vitro and in NIH 3T3 cells in culture,
the level of arginylated CRT increased with the addition of a
Ca2 chelator to the medium, whereas a decreased arginine
incorporation into CRT was found in the presence of Ca2. The
arginylated CRT was observed in the cytosol, in contrast to the
non-arginylated CRT that is in the endoplasmic reticulum.
Under stress conditions, arginylated CRT was found associated
to stress granules. These results suggest that CRT arginylation
occurs in the cytosolic pool of mature CRT (defined by an Asp
acid N-terminal) that is probably retrotranslocated from the
endoplasmic reticulum.
2 chelator to the medium, whereas a decreased arginine
incorporation into CRT was found in the presence of Ca2. The
arginylated CRT was observed in the cytosol, in contrast to the
non-arginylated CRT that is in the endoplasmic reticulum.
Under stress conditions, arginylated CRT was found associated
to stress granules. These results suggest that CRT arginylation
occurs in the cytosolic pool of mature CRT (defined by an Asp
acid N-terminal) that is probably retrotranslocated from the
endoplasmic reticulum.
2. The
arginylated CRT was observed in the cytosol, in contrast to the
non-arginylated CRT that is in the endoplasmic reticulum.
Under stress conditions, arginylated CRT was found associated
to stress granules. These results suggest that CRT arginylation
occurs in the cytosolic pool of mature CRT (defined by an Asp
acid N-terminal) that is probably retrotranslocated from the
endoplasmic reticulum.