| Development of the mammalian central nervous system is a highly orchestrated process dependent on a host of neuronal signaling complexes. Collapsin response mediator protein 2 (CRMP-2), is critical in regulating neuronal polarity through axon/dendrite formation, regulation of growth cone collapse, and assembly of microtubules in extending axons. CRMP-2 has recently been found to interact with a protein called CLN6. CLN6 is a vesicular localized protein with an unknown function, but recent studies have revealed the cytosolic N-terminus of CLN6 interacts with CRMP-2. Mutations in CLN6 result in variant late infantile onset neuronal ceroid lipofuscinosis (vLINCL). Interestingly, CRMP-2 and CLN6 have both been shown to interact with kinesin light chain 4 (KLC4) most likely resulting in a complex with CRMP-2 acting as a scaffold for CLN6 endoplasmic reticulum vesicles to KLC4.;We first set out to characterize the disease condition of the Cln6 nclf mouse and validate its use for the study of vLINCL. Using qRT-PCR we validate the stable expression of a mutant mRNA of a novel truncated Cln6 protein in the Cln6nclf mouse. Further, we demonstrate that the Cln6nclf mouse recapitulates many of the disease phenotypes seen within other animal models of vLINCL, other NCLs, as well as human vLINCL cases. We also introduce evidence that the onset of disease within the Cln6 nclf may be developmental in origin. Together these results confirm that the Cln6nclf mouse is a valid model for vLINCL and the use of this mouse will be vital in the screening of possible therapies.;Next, we set out to further characterize the interaction of CRMP-2/KLC4/CLN6 complex in vitro and in vivo. Attempts to elucidate the interacting domain of CRMP-2 with CLN6 were inconclusive. However, using the Cln6nclf cerebral cortex we demonstrate that the disrupted CLN6 protein alters the dynamics of this interaction as well as additional crucial interactions within the cortex. Combined these results indicate that the nclf mouse represents a valid animal model of vLINCL and that the disruption of CLN6 has further repercussions on the proteomic interactions within the developing and mature Cln6 nclf cortex. |
