Load-dependent ADP binding to myosins V and VI: Implications for subunit coordination and function Export

@article{08pnas105_oguchi_ishiwata, abstract = {10.1073/pnas.0800564105 Dimeric myosins V and VI travel long distances in opposite directions along actin filaments in cells, taking multiple steps in a \^{a}€œhand-over-hand\^{a}€ fashion. The catalytic cycles of both myosins are limited by ADP dissociation, which is considered a key step in the walking mechanism of these motors. Here, we demonstrate that external loads applied to individual actomyosin V or VI bonds asymmetrically affect ADP affinity, such that ADP binds weaker under loads assisting motility. Model-based analysis reveals that forward and backward loads modulate the kinetics of ADP binding to both myosins, although the effect is less pronounced for myosin VI. ADP dissociation is modestly accelerated by forward loads and inhibited by backward loads. Loads applied in either direction slow ADP binding to myosin V but accelerate binding to myosin VI. We calculate that the intramolecular load generated during processive stepping is \^{a}‰ˆ2 pN for both myosin V and myosin VI. The distinct load dependence of ADP binding allows these motors to perform different cellular functions.}, author = {Oguchi, Yusuke and Mikhailenko, Sergey V. and Ohki, Takashi and Olivares, Adrian O. and De La Cruz, Enrique M. and Ishiwata, Shin'ichi}, citeulike-article-id = {3788572}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.0800564105}, citeulike-linkout-1 = {http://www.pnas.org/content/105/22/7714.abstract}, citeulike-linkout-2 = {http://www.pnas.org/content/105/22/7714.full.pdf}, citeulike-linkout-3 = {http://view.ncbi.nlm.nih.gov/pubmed/18509050}, citeulike-linkout-4 = {http://www.hubmed.org/display.cgi?uids=18509050}, day = {3}, doi = {10.1073/pnas.0800564105}, journal = {Proceedings of the National Academy of Sciences}, keywords = {force}, month = {June}, number = {22}, pages = {7714--7719}, posted-at = {2009-11-05 11:29:54}, priority = {2}, title = {Load-dependent ADP binding to myosins V and VI: Implications for subunit coordination and function}, url = {http://dx.doi.org/10.1073/pnas.0800564105}, volume = {105}, year = {2008} }

TY - JOUR ID - 08pnas105_oguchi_ishiwata L3 - citeulike-article-id:3788572 N2 - 10.1073/pnas.0800564105 Dimeric myosins V and VI travel long distances in opposite directions along actin filaments in cells, taking multiple steps in a “hand-over-hand” fashion. The catalytic cycles of both myosins are limited by ADP dissociation, which is considered a key step in the walking mechanism of these motors. Here, we demonstrate that external loads applied to individual actomyosin V or VI bonds asymmetrically affect ADP affinity, such that ADP binds weaker under loads assisting motility. Model-based analysis reveals that forward and backward loads modulate the kinetics of ADP binding to both myosins, although the effect is less pronounced for myosin VI. ADP dissociation is modestly accelerated by forward loads and inhibited by backward loads. Loads applied in either direction slow ADP binding to myosin V but accelerate binding to myosin VI. We calculate that the intramolecular load generated during processive stepping is ≈2 pN for both myosin V and myosin VI. The distinct load dependence of ADP binding allows these motors to perform different cellular functions. IS - 22 JF - Proceedings of the National Academy of Sciences EP - 7719 TI - Load-dependent ADP binding to myosins V and VI: Implications for subunit coordination and function VL - 105 SP - 7714 KW - force AU - Oguchi, Yusuke AU - Mikhailenko, Sergey AU - Ohki, Takashi AU - Olivares, Adrian AU - De La Cruz, Enrique AU - Ishiwata, Shin'ichi PY - 2008/06/03/ UR - http://dx.doi.org/10.1073/pnas.0800564105 ER -