I'm studying a protein that transocates from the cytosol to the nucleus upon hormonal stimulation. I would like to know if this protein is associated with the cytoskeleton (particularly microtubules) in unstimulated cells --or-- if it associates with the cytoskeleton upon hormonal stimulation and is thereby transported to the nucleus.
My current protocol allows me to fractionate cells into triton-soluble and triton-insoluble fractions. The lysis buffer contains glycerol and other components that stabilize microtubules so that the microtubules are equally prevalent in both fractions. Treatment with colchicine causes depolymerization of the microtubules, resulting in their movement to the soluble fraction.
Are there any protocols or kits that allow for fractionation of the cell into distinct cytosol, nuclear, and cytoskeletal fractions AND will stabilize microtubules?