Selective uptake and degradation of c‐Fos and v‐Fos by rat liver lysosomes

FEBS Letters

Knecht, Erwin²  Roche, Enrique³  Aniento, Fernando¹  Papavassiliou, Athanasios G.⁴ 

[1]Dpt. Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Valencia, Burjassot Valencia, Spain

[2]Instituto de Investigaciones Citológicas, Amadeo de Saboya, 4, 46010 Valencia, Spain

[3]Department of Nutrition, University of Montreal, Faculty of Medicine, C.P. 6128 Succursale A, Centre Ville, Montreal H3C 3J7, Que., Canada

[4]Differentiation Programme, European Molecular Biology Laboratory, Meyerhofstrasse, 1, D-69012 Heidelberg, Germany

关键词: Lysosome;    Protein degradation;    c-Fos;    v-Fos;    c-Jun;    Mes;    2-(N-morpholino)ethanesulfonic acid;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;    PAP;    potato acid phosphatase;    TPA;    phorbol 12-myristate 13-acetate;    CQ;    chloroquine;    TREs;    TPA responsive elements;   

DOI  :  10.1016/0014-5793(96)00625-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown