Dynactin-membrane interaction is regulated by the C-terminal domains of p150(Glued).
Dynactin has been proposed to link the microtubule-associated motor cytoplasmic dynein with membranous cargo; however, the mechanism by which dynactin-membrane interaction is regulated is unknown. Here we show that dynein and dynactin exist in discrete cytosolic and membrane-bound states in the filamentous fungus Neurospora crassa. Results from in vitro membrane-binding studies show that dynein and dynactin-membrane interaction is co-dependent. p150(Glued) of dynactin has been shown to interact with dynein intermediate chain and dynactin Arp1 filament; however, it is not known to play a direct role in membrane binding. In this report we describe our analysis of 43 p150(Glued) mutants, and we show that C-terminal deletions which remove the terminal coiled-coil (CC2) and basic domain (BD) result in constitutive dynactin-membrane binding. In vitro addition of recombinant p150(Glued) CC2+BD protein blocks dynactin-membrane binding. We propose that the C-terminal domains of p150(Glued) regulate dynactin-membrane binding through a steric mechanism that controls accessibility of the Arp1 filament of dynactin to membranous cargo.
Kumar
S
S
School of Biological Sciences, University of Missouri-Kansas City, 5100 Rockhill Road, Kansas City, MO 64110-2499, USA.
Zhou
Y
Y
Plamann
M
M
D000483:Alleles; D002462:Cell Membrane / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000072159:Dynactin Complex; D017353:Gene Deletion; D015151:Immunoblotting; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D009492:Neurospora crassa / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D012492:Salts / Q000494:pharmacology; D017422:Sequence Analysis, DNA
D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D011994:Recombinant Proteins; D012492:Salts; D011189:Potassium Chloride