Biomedical Sciences Professor Yoichi Kato has been awarded a National Institutes of Health grant of nearly $365,000 to study the "transition zone" of the cilium.
The cilium is a small cellular organelle that broadly exists throughout the human body. Defects of ciliary structure and/or function in humans cause “ciliopathies,” including retinal degeneration, cardiac defect, airway defect, polycystic kidney, sterility, obesity and mental retardation. The cilium consists of three major parts: basal body, transition zone and axoneme. Many causative factors of ciliopathies have been known to exist in the transition zone, which is important for protein trafficking between the cell cytoplasm and the inside of the cilium. Dysfunction of the transition zone results in no and/or abnormal cilia.
Although the functions of cilia and the mechanisms of cilia formation have been revealed during the past decade, the molecular mechanisms underlying the formation of the transition zone remain to be explored.
It was recently reported that blocking the Smad2/3-dependent TGF-β signal pathway shortened cilia in several different tissues of Xenopus embryos (Tozser et al. 2015). That defect seems to be caused by functional and/or structural problems of the transition zone. In this project, Kato's lab will assess and uncover TGF-β-dependent formation and/or function of the transition zone and discover novel factors involved in the process.