Podocin^{TVV339, 340,341} regulates the surface expression of podocin.

<p>A. Amino acid-triplets within podocin^335–350 were mutated using a Quickchange approach. Mutated plasmids were transiently expressed in HeLa cells and localization of mutants was assessed by immunofluorescence using anti-Flag antibody. In contrast to the other mutants, podocin^{TVV339,340,341AAA} was shown to localize in a predominantly membranous pattern similar to podocin^1–285 (a–d). B. Immunofluorescence of Flag-tagged podocin wild type, podocin^1–285 and podocin^{TVV339, 340,341AAA} confirmed localization in transgenic differentiated podocytes to be analogous to HeLa cells (a–c). C. 293T-cells were transfected with plasmids expressing either CD16-7-*, CD16-7-podocin^286–385 or CD16-7-podocin^{286–385 TVV339,340,341AAA} and cell surface expression was analyzed by FACS. As transfected cells also expressed Gfp driven from an internal ribosomal site from the same vector, gates were set to include Gfp-positive cells only. Cell surface expression of CD16-7-* and CD16-7-podocin^{286–385TVV339,340,341AAA,} was comparable (b), while less CD16-7-podocin^286–385 could be detected at the plasma membrane, consistent with a role of podocin^{TVV339,340,341} in regulating internalization of podocin (a).