Work in my lab focuses on the force generating mechanisms of kinesins and microtubules. Using a combination of protein engineering, rapid kinetic analysis and single molecule microscopy, we have shown for example that dimeric kinesin motors can be driven to walk backwards under load, that the binding of one motor domain to tubulin (the building block of microtubules) is controlled by ATP-binding to the other, and that the individual mechanical steps of the motor happen on the microsecond timescale.
We have worked extensively with microtubules in the fission yeast S. pombe, and were the first to describe the in vivo dynamics of the interphase S. pombe microtubule cytoskeleton. We have developed a biochemical purification for S. pombe tubulin and have used this to understand how plus end tracking proteins influence the structure and dynamics of S. pombe microtubules. In order to address these problems, we have developed our own optical microscopes. Recently, we harnessed this experience to construct the WOSM (Warwick Open Source Microscope), a super-stable open source platform for super resolution microscopy and optical trapping. The WOSM is already the basis of a number of collaborative projects at Warwick and elsewhere. Our current work is aimed at digging deeper into the fundamental mechanisms that allow kinesin motors to exert directional force on tubulin, and into the operation of these mechanisms in teams of kinesins interacting with dynamic microtubules. We are also aiming, via collaborations, to understand how kinesin-tubulin interactions contribute to the patterning of force generation in cells. Forces generated by kinesins and microtubules drive much of the self-organisation behaviour of eukaryotic cells. Understanding the force-generating mechanism is therefore important, not just for fundamental science, but also for the development of improved chemical biology approaches to a range of important medical and agricultural problems.
M. Britto, A. Goulet, S. Rizvi, O. von Loeffelholz, C. A. Moores, and R. A. Cross (2016)
Schizosaccharomyces pombe kinesin-5 switches direction using a steric blocking mechanism
PNAS doi: 10.1073/pnas.1611581113
R.A. Cross (2016)
Mechanochemistry of the kinesin-1 ATPase
Biopolymers doi: 10.1002/bip.22862
F. Hussmann, D. R. Drummond, D. Peet, D. S. Martin & R. A. Cross (2016)
Alp7/TACC-Alp14/TOG generates long-lived, fast-growing MTs by an unconventional mechanism
Scientific Reports doi: 10.1038/srep20653
Katsuki, M., Drummond, D.R. & Cross, R.A. (2014)
Ectopic A-lattice seams destabilise microtubules
Nature Communications doi: 10.1038/ncomms4094
Grant, B.J., Gheorghe, D., Zheng,W., Alonso, M., Huber, G., Dlugosz,M., McCammon, J.A. & Cross, R.A. (2011)
Electrostatically biased binding of kinesin to microtubules
PLOS Biology 9(11) e1001207.
Alonso,M.C., Drummond, D.R., Kain, S., Hoeng, J., Amos, L.A. & Cross, R.A. (2007)
An ATP-gate controls tubulin binding by the tethered head of kinesin-1
Science 316 120-123
Carter N.J. & Cross R.A. (2005)
Mechanics of the kinesin step
Nature 435 308-12