Pkd1 and Pkd2 encode the polycystin proteins which underlie human ADPKD, a major cause of end stage renal failure. Recently, by analysing the Pkd2lrm4 mouse, a previous member of the lab provided evidence that loss of ciliary PKD2 underlies kidney cyst formation. Furthermore, the Pkd2lrm4 mouse highlights a requirement for PKD2 in nodal cilia for correct L-R patterning. However, we are yet to fully understand its cilia-specific role and the mechanisms controlling its ciliary trafficking and entry. PKD1L1 (a PKD1 Paralog) functions with PKD2 in the embryonic node to allow correct L-R patterning and its expression and localisation during this process remain to be fully characterized.
By generating endogenously tagged alleles of PKD1L1 and PKD2, I have investigated their localisation and co-localisation, in the embryonic node during L-R determination. Using these tagged alleles, Pkd1l1mTFP1 and Pkd2mNG, I have been able to evaluate their localisation in Pkd2-/- and Pkd1l1-/- embryos respectively. Enabling us to further understand the role of their co-localisation, and assess the co-dependent relationship between PKD2 and PKD1L1 for ciliary localisation. Using Pkd2lrm4/lrm4 samples, I have been able to identify a selection of candidate interacting proteins that may be involved in trafficking to cilia and ciliary entry of PKD2.
The work in this thesis provides a new insight into the genetic and molecular mechanisms involved with the polycystins, and their roles in left-right pattern determination
