Furin and proprotein convertase 7 (PC7)/lymphoma PC endogenously expressed in rat liver can be resolved into distinct post-Golgi compartments.
The intracellular compartmentalization in rat liver of the membrane-associated convertases furin and proprotein convertase 7 (PC7)/lymphoma PC (LPC) was investigated by analytical subcellular fractionation. In control animals, both enzymes were found to localize in fractions depleted of endoplasmic reticulum, cis-Golgi and lysosomal markers, but to co-distribute with the Golgi marker galactosyltransferase and the trans-Golgi network (TGN) marker TGN38. After overloading Golgi-derived vesicles with very-low-density lipoproteins (VLDL) by feeding rats with ethanol, the distribution of PC7/LPC was shifted markedly towards lower densities, in contrast with those of furin and the TGN marker. This provides support for the TGN localization of endogenously expressed furin and indicates that, at steady state, a considerable proportion of PC7/LPC may be associated with vesicles derived from the TGN.
Wouters
S
S
Laboratoire de Chimie Physique des Macromolécules aux Interfaces (LCPMI), CP206/2, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050 Brussels, Belgium. swouters@ulb.ac.be
Leruth
M
M
Decroly
E
E
Vandenbranden
M
M
Creemers
J W
JW
van de Loo
J W
JW
Ruysschaert
J M
JM
Courtoy
P J
PJ
D000818:Animals; D000431:Ethanol / Q000494:pharmacology; D045683:Furin; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions; D013381:Subtilisins / Q000378:metabolism*
D006023:Glycoproteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C513045:Tgoln2 protein, rat; D000431:Ethanol; D013381:Subtilisins; C107583:proprotein convertase PC7; D045683:Furin