title: Microtubule C-Terminal Tails Can Change Characteristics of Motor Force Production.
abstract: Control of intracellular transport is poorly understood, and functional ramifications of tubulin isoform differences between cell types are mostly unexplored. Motors' force production and detachment kinetics are critical for their group function, but how microtubule (MT) details affect these properties--if at all--is unknown. We investigated these questions using both a vesicular transport human kinesin, kinesin-1, and also a mitotic kinesin likely optimized for group function, kinesin-5, moving along either bovine brain or MCF7(breast cancer) MTs. We found that kinesin-1 functioned similarly on the two sets of MTs--in particular, its mean force production was approximately the same, though due to its previously reported decreased processivity, the mean duration of kinesin-1 force production was slightly decreased on MCF7 MTs. In contrast, kinesin-5's function changed dramatically on MCF7 MTs: its average detachment force was reduced and its force-velocity curve was different. In spite of the reduced detachment force, the force-velocity alteration surprisingly improved high-load group function for kinesin-5 on the cancer-cell MTs, potentially contributing to functions such as spindle-mediated chromosome separation. Significant differences were previously reported for C-terminal tubulin tails in MCF7 versus bovine brain tubulin. Consistent with this difference being functionally important, elimination of the tails made transport along the two sets of MTs similar.
authors.affiliation: Department of Physics, Seton Hall University, South Orange, NJ 07079, USA.|Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Mitra
authors.initials: M
authors.lastname: Shojania Feizabadi
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Babu Reddy
authors.initials: BR
authors.lastname: Janakaloti Narayanareddy
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Omid
authors.initials: O
authors.lastname: Vadpey
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Yonggun
authors.initials: Y
authors.lastname: Jun
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Dail
authors.initials: D
authors.lastname: Chapman
authors.affiliation: Department of Cancer Biology, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Rosenfeld
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, CA 92697, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gross
mesh_terms: D000818:Animals; D002417:Cattle; D045744:Cell Line, Tumor; D006801:Humans; D016547:Kinesins / Q000378:metabolism; D007700:Kinetics; D061986:MCF-7 Cells; D008870:Microtubules / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*; D014404:Tubulin / Q000378:metabolism
chemical_list: D014404:Tubulin; D016547:Kinesins
keywords: C-terminal; Eg5; force production; kinesin-1; microtubule