Neurodegenerative diseases represent an increasing practical and financial burden on developed societies. Parkinson's Disease, affecting dopaminergic neurons, is one such disease, affecting ~1% of people over 60 in the UK. While most PD is idiopathic, ~15% is attributable to genetic causes. Of this, a significant proportion is linked to mutations in LRRK2, a Leucine-Rich Repeat Kinase; implicated in diverse cellular processes, from membrane traffic to mitochondria. The highly conserved C. elegans orthologue of LRRK2,
lrk-1, interacts with
unc-101, encoding a component of the AP-1 complex - important in post-Golgi transport, to regulate the localisation of synaptic vesicle proteins (SV) (Sakaguchi-Nakashima et al., 2007). We show here that these genes also interact to affect transport to the cilia of dopaminergic neurons. Perturbing
unc-101, clathrin and
rab-8 misroutes ODR-10, normally localized to the cilia, to all membrane compartments and that there is a requirement for the critical endocytosis proteins, clathrin,
dyn-1 and the AP-2 complex in regulating cilium membrane volume (Dwyer et al., 2001, Kaplan et al., 2010, 2012). Using the dopamine transporter, DAT-1, fused to YFP, we show that it is excluded from the cilia of dopaminergic neurons, contrary to ODR-10, in wild type worms. In
unc-101, and
unc-16, a scaffold protein, mutants DAT-1 is misrouted to the cilia. Mutations in AP-2,
dyn-1, &
rab-8 did not result in DAT-1 misrouting, suggesting a novel role for the AP-1 complex in sorting cargoes away from the cilia or in establishing a membrane diffusion barrier at the base of the cilium. A
lrk-1 mutation enhances the above DAT-1 ciliary misrouting phenotype, in contrast to the latter's rescuing effect on SV proteins. This suggests that
lrk-1 may be a cargo dependent regulator of
unc-101. Using a LRK-1::GFP we show that it is expressed in dopaminergic neurons and hope to study its localisation and protein interactions to further elucidate function. Additionally, we have performed mutagenesis screens for DAT-1 cilia misrouting phenotypes and have isolated several independent mutations. We hope that these will offer new insight into cilia establishment and maintenance.