Ubiquitinated protein conjugates are specifically enriched in the lysosomal system of fibroblasts

FEBS Letters

Doherty, Fergus J.²  John Mayer, R.²  Laszlo, Lajos¹  Osborn, Natasha U.² 

[1] Department of General Zoology, ELTE University, Puskin U.3, H-1088 Budapest, Hungary;Department of Biochemistry, University of Nottingham Medical School, Queens Medical Centre, Clifton Boulevard, Nottingham, NG7 2UH, England

关键词: Ubiquitin;    Lysosome;    Epoxysuccinyl-leucylamido-(4-guanadino)butane;    Electron microscopy;    (3T3-L1 fibroblasts);    E-64;    epoxysuccinyl-leucylamido-(4-guanidino)butane;    LDH;    lactate dehydrogenase;   

DOI  :  10.1016/0014-5793(90)80593-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ubiquitin-protein conjugates are found by imniunogold electron microscopy to be enriched (12-fold) in the lysosomal compartment of 3T3-L1 fibroblasts. Treatment of fibroblasts with the cysteine protease inhibitor E-64 leads to an expansion of the lysosomal compartment and as a result an increase in the cellular content of ubiquitin-protein conjugates. There is no change in the specific enrichment of ubiquitin-protein conjugates in the lysosomal compartment following E-64 treatment. The results suggest that some ubiquitin-protein conjugates may normally be degraded lysosomally following sequestration by microautophagy and imply that protein ubiquitination may be one of the signals for protein uptake into lysosomes.

【 授权许可】

Unknown