Microtubule-dependent movement of late endocytic vesicles in vitro: requirements for Dynein and Kinesin.
Our previous studies demonstrated that fluorescent early endocytic vesicles prepared from rat liver after injection of Texas red asialoorosomucoid contain asialoglycoprotein and its receptor and move and undergo fission along microtubules using kinesin I and KIFC2, with Rab4 regulating KIFC2 activity (J. Cell Sci. 116, 2749, 2003). In the current study, procedures to prepare fluorescent late endocytic vesicles were devised. In addition, flow cytometry was utilized to prepare highly purified fluorescent endocytic vesicles, permitting validation of microscopy-based experiments as well as direct biochemical analysis. These studies revealed that late vesicles bound to and moved along microtubules, but in contrast to early vesicles, did not undergo fission. As compared with early vesicles, late vesicles had reduced association with receptor, Rab4, and kinesin I but were highly associated with dynein, Rab7, dynactin, and KIF3A. Dynein and KIF3A antibodies inhibited late vesicle motility, whereas kinesin I and KIFC2 antibodies had no effect. Dynamitin antibodies prevented the association of late vesicles with microtubules. These results indicate that acquisition and exchange of specific motor and regulatory proteins characterizes and may regulate the transition of early to late endocytic vesicles. Flow cytometric purification should ultimately facilitate detailed proteomic analysis and mapping of endocytic vesicle-associated proteins.
Bananis
Eustratios
E
Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Nath
Sangeeta
S
Gordon
Kristie
K
Satir
Peter
P
Stockert
Richard J
RJ
Murray
John W
JW
Wolkoff
Allan W
AW
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001692:Biological Transport; D000072159:Dynactin Complex; D004398:Dyneins / Q000032:analysis / Q000502:physiology*; D016547:Kinesins / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000276:immunology / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000276:immunology; D051381:Rats; D022161:Transport Vesicles / Q000378:metabolism*; D020691:rab GTP-Binding Proteins / Q000032:analysis / Q000378:metabolism; D020695:rab4 GTP-Binding Proteins / Q000032:analysis / Q000378:metabolism; D000090802:rab7 GTP-Binding Proteins
D000906:Antibodies; D000072159:Dynactin Complex; C490201:Kif3a protein, rat; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D000090802:rab7 GTP-Binding Proteins; C000716466:rab7 GTP-binding proteins, rat; D004398:Dyneins; D016547:Kinesins; D020691:rab GTP-Binding Proteins; D020695:rab4 GTP-Binding Proteins