Binding of Hsp90 to the LIMK proteins protects them from degradation and promotes their dimer formation and transphosphorylation. It is estimated that LIMK1 contains at least 5 phospho-amino acids primarily phospho-serines, in its kinase domain. The positions of these serine residues are not known. Transphosphorylation of these serine residues in LIMK1 increases its stability.