Interaction of casein kinase 1 delta (CK1δ) with the light chain LC2 of microtubule associated protein 1A (MAP1A)

CK1δ, a member of the casein kinase 1 family of serine/threonine specific kinases, has been shown to be involved in the regulation of microtubule dynamics. We have now identified a 176 aa fragment of the light chain LC2 of MAP1A (termed LC2-P16) specifically interacting with CK1δ. Two CK1δ interacting domains of LC2 were identified, located between aa 2629 and 2753 close to aa 2683 and between aa 2712 and 2805 of LC2. The two regions necessary for the interaction of LC2 with CK1δ have been mapped between aa 76-103 and aa 351-375 of CK1δ. Furthermore, LC2 has been identified as a new substrate of CK1δ. We therefore propose a model in which CK1δ could modulate microtubule dynamics by changing the phosphorylation status of the light chain LC2 of MAP1A.