Search

Objective: The Uncoordinated 5A (UNC5A) protein is part of a family of receptors that play roles in axonal pathfinding and cell migration. We previously showed that the Fanconi anemia C protein (FANCC) interacts with UNC5A and delays UNC5A-mediated apoptosis. FANCC is a predominantly cytoplasmic protein that has multiple functions including DNA damage signaling, oxygen radical metabolism, signal transduction, transcriptional regulation and apoptosis. Given the direct interaction between FANCC and UNC5A and that FANCC interferes with UNC5A-mediated apoptosis, we explored the possibility that FANCC might play a role in axonal-like growth processes., Results: Here we show that FANCC and UNC5A are localized to regions of neurite outgrowth during neuronal cell differentiation. We also show that absence of FANCC is required for neurite outgrowth. In addition, FANCC seems required for UNC5A expression. Results from this study combined with our previous report suggest that FANCC plays a role in tissue development through the regulation of UNC5A-mediated functions.

The Fanconi anemia group C protein (FANCC) is one of the several proteins that comprise the Fanconi anemia (FA) network involved in genomic surveillance. FANCC is mainly cytoplasmic and has many functions, including apoptosis suppression through caspase-mediated proteolytic processing. Here, we examined the role of FANCC proteolytic fragments by identifying their binding partners. We performed a yeast two-hybrid screen with caspase-mediated FANCC cleavage products and identified the dependence receptor uncoordinated-5A (UNC5A) protein. Here, we show that FANCC physically interacts with UNC5A, a pro-apoptotic dependence receptor. FANCC interaction occurs through the UNC5A intracellular domain, specifically via its death domain. FANCC modulates cell sensitivity to UNC5A-mediated apoptosis; we observed reduced UNC5A-mediated apoptosis in the presence of FANCC and increased apoptosis in FANCC-depleted cells. Our results show that FANCC interferes with UNC5A's functions in apoptosis and suggest that FANCC may participate in developmental processes through association with the dependence receptor UNC5A.