The uroplakins form tiny, hexagonal arrays of particles--visualized best by electron microscopy (see figure taken from this excellent recent KI review by Wu et al)--which comprise structures called "urothelial plaques" that overlie the plasma membrane of superficial umbrella cells of the urothelium...Read more here.
I'm Dr. Joshua Schwimmer, a nephrologist and internal medicine physician in New York City. • Kidney Notes was the first active nephrology blog. (Trivia: Kidney Notes is so old that the National Library of Medicine still uses it as an example of how to formally cite blogs.) • Professionally, you can find me at Kidney.nyc. • Kidney Notes is for educational purposes only, not medical advice. Consult qualified health care professionals. See disclaimer.