CFAP54 is required for proper ciliary motility and assembly of the central pair apparatus in mice.

Motile cilia and flagella play critical roles in fluid clearance and cell motility, and dysfunction commonly results in the pediatric syndrome primary ciliary dyskinesia (PCD). CFAP221, also known as PCDP1, is required for ciliary and flagellar function in mice and Chlamydomonas reinhardtii, where it localizes to the C1d projection of the central microtubule apparatus and functions in a complex that regulates flagellar motility in a calcium-dependent manner. We demonstrate that the genes encoding the mouse homologues of the other C. reinhardtii C1d complex members are primarily expressed in motile ciliated tissues, suggesting a conserved function in mammalian motile cilia. The requirement for one of these C1d complex members, CFAP54, was identified in a mouse line with a gene-trapped allele. Homozygous mice have PCD characterized by hydrocephalus, male infertility, and mucus accumulation. The infertility results from defects in spermatogenesis. Motile cilia have a structural defect in the C1d projection, indicating that the C1d assembly mechanism requires CFAP54. This structural defect results in decreased ciliary beat frequency and perturbed cilia-driven flow. This study identifies a critical role for CFAP54 in proper assembly and function of mammalian cilia and flagella and establishes the gene-trapped allele as a new model of PCD

Senior Thesis Proposal

Senior Thesis Proposa

The Role of Glutamate Receptors in the Pathophysiology and Treatment of Infantile Neuronal Ceroid Lipofuscinosis

Thesis (Ph.D.)--University of Rochester. School of Medicine & Dentistry. Dept. of Biochemistry and Biophysics, 2012.The neuronal ceroid lipofuscinoses (NCLs) are a group of lysosomal storage disorders that represent the most common form of pediatric-onset neurodegeneration. Of these diseases, infantile NCL (INCL) is the most rapidly progressing variant and has the earliest onset. Beginning at approximately six months of age, affected children experience retinal degeneration which results in blindness followed by neurocognitive decline, seizures, and premature death. Currently, the only available treatments are purely palliative due to our limited understanding of the biochemistry that drives neuronal loss in INCL. Studies suggesting that disruptions in glutamatergic function may contribute to INCL disease progression drove us to examine glutamate receptor function in the Ppt1-/- mouse model of the disease. Investigation of glutamate receptor function in cerebellar granule cells isolated from this mouse model uncovered a decrease in AMPA receptor function and an increase in NMDA receptor function. As glutamate receptor function is regulated in part by the surface expression level of the receptor, the surface levels of AMPA and NMDA receptor subunits in the cerebella of four-week-old WT and Ppt1-/- mice were also examined. This examination showed a significantly lower surface level of the GluR4 AMPA receptor subunit in the Ppt1-/- cerebella, providing a plausible explanation for the decreased vulnerability of Ppt1-/- cultured granule cells to AMPA-mediated cell death. These described alterations in glutamate receptor function within the cerebellum of the Ppt1-/- mouse have enormous potential as a therapeutic target for the treatment of INCL. This investigation is made feasible by the availability of positive allosteric modulators of AMPA receptors and NMDA receptor antagonists. At an advanced stage of the disease, Ppt1-/- mice were given a single dose of memantine, an NMDA receptor antagonist, and their motor coordination was assessed using an accelerating rotarod. This treatment notably improved motor learning in the Ppt1-/- mice. Taken together, this work has uncovered significant aberrations in the brain of the Ppt1-/-mouse model of INCL and has begun the process of developing a therapeutic strategy based on that biochemical abnormality