CD47 plays a role in nitric oxide signaling and angiogenesis by interacting with other proteins like thrombospondin-1 and vascular endothelial growth factor receptor-2. The document discusses experiments attempting to characterize CD47's role by tagging it with BirA to identify interacting proteins, expressing a truncated version of thrombospondin-1 to activate CD47 and measure calcium responses, and cloning CD47-BirA into a vector for expression. Preliminary results were inconclusive, suggesting the calcium assay and thrombospondin-1 purification need further optimization to understand CD47's signaling mechanisms.