Selective uptake and degradation of c-Fos and v-Fos by rat liver lysosomes.
FEBS Lett
; 390(1): 47-52, 1996 Jul 15.
Article
in En
| MEDLINE
| ID: mdl-8706827
ABSTRACT
The transcription factor c-Fos is a short-lived protein and calpains and ubiquitin-dependent systems have been proposed to be involved in its degradation. In this report, we consider a lysosomal degradation pathway for c-Fos. Using a cell-free assay, we have found that freshly isolated lysosomes can take up and degrade c-Fos with high efficiency. v-Fos, the oncogenic counterpart of c-Fos, can also be taken up by lysosomes, yet the amount of incorporated protein is much lower. c-Fos uptake is independent of its phosphorylation state but it appears to be regulated by dimerization with differentially phosphorylated forms of c-Jun, while v-Fos escapes this regulation. Moreover, we show that c-Fos is immunologically detected in lysosomes isolated from the liver of rats treated with the protease inhibitor leupeptin. Altogether, these results suggest that lysosomes can also participate in the selective degradation of c-Fos in rat liver.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Proto-Oncogene Proteins c-fos
/
Oncogene Proteins v-fos
/
Liver
/
Lysosomes
Limits:
Animals
/
Humans
Language:
En
Journal:
FEBS Lett
Year:
1996
Document type:
Article
Affiliation country: