Forces due to curving protofilaments in microtubules.
Microtubules consist of 13 protofilaments arranged in the form of a cylinder. The protofilaments are composed of longitudinally attached tubulin dimers that can exist in either a less curved state [GTP-bound tubulin (T)] or a more curved state [GDP-bound tubulin (D)]. Hydrolysis of T into D leaves the straight and laterally attached protofilaments of the microtubule in a mechanically stressed state, thus leading to their unzipping. The elastic energy in the unzipping protofilaments can be harnessed by a force transducer such as the Dam1-kinetochore ring complex in order to exert pulling force on chromosomes during cell division. In the present paper we develop a simple continuum model to obtain this pulling force as a function of the mechanical properties of protofilaments and the size of the Dam1-kinetochore ring. We also extend this model to investigate the role played by the T subunits found at the plus end of the microtubule (the T cap) on the mechanical stability of microtubules.
Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
Shirish
S
Vichare
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
Ishutesh
I
Jain
Department of Civil Engineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
Mandar M
MM
Inamdar
Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India.
Ranjith
R
Padinhateeri
D001696:Biomechanical Phenomena; D003599:Cytoskeleton / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism; D055595:Mechanical Phenomena; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D014404:Tubulin / Q000378:metabolism
D014404:Tubulin; D006160:Guanosine Triphosphate