Linked Life Data

21680740

Source:http://linkedlifedata.com/resource/pubmed/id/21680740

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
2011-8-15
pubmed:abstractText
Kar3Cik1 is a Saccharomyces cerevisiae kinesin-14 that functions to shorten cytoplasmic microtubules (MTs) during yeast mating yet maintains mitotic spindle stability by cross-linking anti-parallel interpolar MTs. Kar3 contains both an ATP- and a MT-binding site, yet there is no evidence of a nucleotide-binding site in Cik1. Presteady-state and steady-state kinetic experiments were pursued to define the regulation of Kar3Cik1 interactions with the MT lattice expected during interpolar MT cross-linking. The results reveal that association of Kar3Cik1 with the MT occurs at 4.9 ?M(-1) s(-1), followed by a 5-s(-1) structural transition that limits ADP release from the Kar3 head. Mant-ATP binding occurred at 2.1 ?M(-1) s(-1), and the pulse-chase experiments revealed an ATP-promoted isomerization at 69 s(-1). ATP hydrolysis was observed as a rapid step at 26 s(-1) and was required for the Kar3Cik1 motor to detach from MT. The conformational change at 5 s(-1) that occurred after Kar3Cik1 MT association and prior to ADP release was hypothesized to be the rate-limiting step for steady-state ATP turnover. We propose a model in which Kar3Cik1 interacts with the MT lattice through an alternating cycle of Cik1 MT collision followed by Kar3 MT binding with head-head communication between Kar3 and Cik1 modulated by the Kar3 nucleotide state and intramolecular strain.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
19
pubmed:volume
286
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29261-72
pubmed:dateRevised
2011-10-19
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Kinesin Kar3Cik1 ATPase pathway for microtubule cross-linking.
pubmed:affiliation
Department of Biology and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural