Description
The cytoskeleton is a complex composite network of proteins, including filamentous proteins such as actin and microtubules, as well as numerous binding proteins that crosslink these filaments. The physical interactions between semiflexible actin filaments and rigid microtubules, as well as the wide range of crosslinking motifs that their corresponding binding proteins offer, allow cells to precisely tune their strength and structure to support mechanical processes such as apoptosis and meiosis. To determine the role that crosslinking versus steric interactions has on cytoskeleton composites we: (1) design composites of co-entangled actin and microtubules with varying crosslinking motifs, and (2) use optical tweezers microrheology and dual-color confocal microscopy to characterize the mechanics and structure of composites. Specifically, we create equimolar actin-microtubule composites in which only actin is crosslinked, only microtubules are crosslinked, and both filaments are co-crosslinked. We then measure the force response resulting from optically driving microspheres through the composites; and image spectrally distinct actin and microtubules to quantify composite mobility and morphology.
The Effect of Varying Crosslinking Motifs on the Microscale Mechanics of Co-entangled Actin and Microtubules
The cytoskeleton is a complex composite network of proteins, including filamentous proteins such as actin and microtubules, as well as numerous binding proteins that crosslink these filaments. The physical interactions between semiflexible actin filaments and rigid microtubules, as well as the wide range of crosslinking motifs that their corresponding binding proteins offer, allow cells to precisely tune their strength and structure to support mechanical processes such as apoptosis and meiosis. To determine the role that crosslinking versus steric interactions has on cytoskeleton composites we: (1) design composites of co-entangled actin and microtubules with varying crosslinking motifs, and (2) use optical tweezers microrheology and dual-color confocal microscopy to characterize the mechanics and structure of composites. Specifically, we create equimolar actin-microtubule composites in which only actin is crosslinked, only microtubules are crosslinked, and both filaments are co-crosslinked. We then measure the force response resulting from optically driving microspheres through the composites; and image spectrally distinct actin and microtubules to quantify composite mobility and morphology.