Why kinesin is so processive

Erdal Toprak, Ahmet Yildiz, Melinda Tonks Hoffman, Steven S. Rosenfeld, Paul R. Selvin

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of kinesin stepping, and our results lead to 4 conclusions. First, under physiologic conditions, ≈75% of processively moving kinesin molecules are attached to the microtubule via both heads, and in this conformation, they are resistant to dissociation. Second, the remaining 25% of kinesin molecules, which are in an "ATP waiting state" and are strongly attached to the microtubule via only one head, are intermittently in a conformation that cannot bind ATP and therefore are resistant to nucleotide-induced dissociation. Third, the forward step in the kinesin ATPase cycle is very fast, accounting for <5% of the total cycle time, which ensures that the lifetime of this ATP waiting state is relatively short. Finally, by combining nanometer-level single-molecule fluorescence localization with higher ATP concentrations than used previously, we have determined that in this ATP waiting state, the ADP-containing head of kinesin is located 8 nm behind the attached head, in a location where it can interact with the microtubule lattice. These 4 features reduce the likelihood that a kinesin I motor will dissociate and contribute to making this motor so highly processive.

Original languageEnglish (US)
Pages (from-to)12717-12722
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume106
Issue number31
DOIs
StatePublished - Aug 4 2009

Fingerprint

Kinesin
Microtubules
Adenosine Triphosphate
Head
Fluorescence
Adenosine Diphosphate
Adenosine Triphosphatases
Nucleotides

Keywords

  • Fluorescence
  • Fluorescence imaging with 1-nm accuracy
  • Gating
  • Motility
  • Processivity

ASJC Scopus subject areas

  • General

Cite this

Why kinesin is so processive. / Toprak, Erdal; Yildiz, Ahmet; Hoffman, Melinda Tonks; Rosenfeld, Steven S.; Selvin, Paul R.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, No. 31, 04.08.2009, p. 12717-12722.

Research output: Contribution to journalArticle

Toprak, Erdal ; Yildiz, Ahmet ; Hoffman, Melinda Tonks ; Rosenfeld, Steven S. ; Selvin, Paul R. / Why kinesin is so processive. In: Proceedings of the National Academy of Sciences of the United States of America. 2009 ; Vol. 106, No. 31. pp. 12717-12722.
@article{4af90950cea44d89be9d0c2edf47b4bc,
title = "Why kinesin is so processive",
abstract = "Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of kinesin stepping, and our results lead to 4 conclusions. First, under physiologic conditions, ≈75{\%} of processively moving kinesin molecules are attached to the microtubule via both heads, and in this conformation, they are resistant to dissociation. Second, the remaining 25{\%} of kinesin molecules, which are in an {"}ATP waiting state{"} and are strongly attached to the microtubule via only one head, are intermittently in a conformation that cannot bind ATP and therefore are resistant to nucleotide-induced dissociation. Third, the forward step in the kinesin ATPase cycle is very fast, accounting for <5{\%} of the total cycle time, which ensures that the lifetime of this ATP waiting state is relatively short. Finally, by combining nanometer-level single-molecule fluorescence localization with higher ATP concentrations than used previously, we have determined that in this ATP waiting state, the ADP-containing head of kinesin is located 8 nm behind the attached head, in a location where it can interact with the microtubule lattice. These 4 features reduce the likelihood that a kinesin I motor will dissociate and contribute to making this motor so highly processive.",
keywords = "Fluorescence, Fluorescence imaging with 1-nm accuracy, Gating, Motility, Processivity",
author = "Erdal Toprak and Ahmet Yildiz and Hoffman, {Melinda Tonks} and Rosenfeld, {Steven S.} and Selvin, {Paul R.}",
year = "2009",
month = "8",
day = "4",
doi = "10.1073/pnas.0808396106",
language = "English (US)",
volume = "106",
pages = "12717--12722",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
number = "31",

}

TY - JOUR

T1 - Why kinesin is so processive

AU - Toprak, Erdal

AU - Yildiz, Ahmet

AU - Hoffman, Melinda Tonks

AU - Rosenfeld, Steven S.

AU - Selvin, Paul R.

PY - 2009/8/4

Y1 - 2009/8/4

N2 - Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of kinesin stepping, and our results lead to 4 conclusions. First, under physiologic conditions, ≈75% of processively moving kinesin molecules are attached to the microtubule via both heads, and in this conformation, they are resistant to dissociation. Second, the remaining 25% of kinesin molecules, which are in an "ATP waiting state" and are strongly attached to the microtubule via only one head, are intermittently in a conformation that cannot bind ATP and therefore are resistant to nucleotide-induced dissociation. Third, the forward step in the kinesin ATPase cycle is very fast, accounting for <5% of the total cycle time, which ensures that the lifetime of this ATP waiting state is relatively short. Finally, by combining nanometer-level single-molecule fluorescence localization with higher ATP concentrations than used previously, we have determined that in this ATP waiting state, the ADP-containing head of kinesin is located 8 nm behind the attached head, in a location where it can interact with the microtubule lattice. These 4 features reduce the likelihood that a kinesin I motor will dissociate and contribute to making this motor so highly processive.

AB - Kinesin I can walk on a microtubule for distances as long as several micrometers. However, it is still unclear how this molecular motor can remain attached to the microtubule through the hundreds of mechanochemical cycles necessary to achieve this remarkable degree of processivity. We have addressed this issue by applying ensemble and single-molecule fluorescence methods to study the process of kinesin stepping, and our results lead to 4 conclusions. First, under physiologic conditions, ≈75% of processively moving kinesin molecules are attached to the microtubule via both heads, and in this conformation, they are resistant to dissociation. Second, the remaining 25% of kinesin molecules, which are in an "ATP waiting state" and are strongly attached to the microtubule via only one head, are intermittently in a conformation that cannot bind ATP and therefore are resistant to nucleotide-induced dissociation. Third, the forward step in the kinesin ATPase cycle is very fast, accounting for <5% of the total cycle time, which ensures that the lifetime of this ATP waiting state is relatively short. Finally, by combining nanometer-level single-molecule fluorescence localization with higher ATP concentrations than used previously, we have determined that in this ATP waiting state, the ADP-containing head of kinesin is located 8 nm behind the attached head, in a location where it can interact with the microtubule lattice. These 4 features reduce the likelihood that a kinesin I motor will dissociate and contribute to making this motor so highly processive.

KW - Fluorescence

KW - Fluorescence imaging with 1-nm accuracy

KW - Gating

KW - Motility

KW - Processivity

UR - http://www.scopus.com/inward/record.url?scp=69149085424&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=69149085424&partnerID=8YFLogxK

U2 - 10.1073/pnas.0808396106

DO - 10.1073/pnas.0808396106

M3 - Article

VL - 106

SP - 12717

EP - 12722

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 31

ER -