Interaction of the microtubule cytoskeleton with endocytic vesicles and cytoplasmic dynein in cultured rat hepatocytes.
In a recent study (Goltz, J.S., Wolkoff, A.W., Novikoff, P.M., Stockert, R.J., and Satir, P. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 7026-7030), we found that ligand- and receptor-containing endocytic vesicles bind to endogenous microtubules in vitro after 60 min of receptor-mediated endocytosis of asialo-orosomucoid. In the presence of ATP, ligand-containing endocytic vesicles are released from microtubules, while those containing receptor are not. We hypothesized that cytoplasmic dynein may associate with ligand-containing, but not receptor-containing, domains of endocytic vesicles and might be involved in the movement of ligand-containing vesicles along microtubules during sorting of ligand from receptor. Direct evidence in support of this hypothesis has been obtained in the present study. Binding of ligand-containing vesicles to microtubules correlates highly (p < 0.001) with binding of dynein, but not kinesin, under a variety of conditions. Binding of receptor-containing vesicles to microtubules is independent of both cytoplasmic dynein and kinesin binding. Tight association of cytoplasmic dynein with a population of ligand-containing vesicles is seen directly by immunoprecipitation. These results support the view that in receptor-mediated endocytosis, ligand-containing vesicles become bound to microtubules by cytoplasmic dynein. While receptor domains of endosomes remain attached to microtubules in an ATP-independent manner, ligand-containing domains might be moved away toward pericentrosomal lysosomes by this motor molecule.
Oda
H
H
Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Stockert
R J
RJ
Collins
C
C
Wang
H
H
Novikoff
P M
PM
Satir
P
P
Wolkoff
A W
AW
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins / Q000378:metabolism; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure*; D004398:Dyneins / Q000378:metabolism*; D004705:Endocytosis; D006801:Humans; D016547:Kinesins / Q000378:metabolism; D007700:Kinetics; D008024:Ligands; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure*; D008297:Male; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure*; D009961:Orosomucoid / Q000031:analogs & derivatives / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012265:Ribonucleotides / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism
D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D008024:Ligands; D009961:Orosomucoid; D011956:Receptors, Cell Surface; D012265:Ribonucleotides; D014404:Tubulin; C017030:asialoorosomucoid; D000255:Adenosine Triphosphate; D004398:Dyneins; D016547:Kinesins