FIG 7.

U21 multimerizes in vivo. (a) Schematic of the U21tm_TEVHAHA-tail construct, with amino acid numbers, signal sequence (white), transmembrane domain (blue), TEV cleavage site (orange), and the tandem HA tags (green). (b) Immunoprecipitations of metabolically labeled U21- or U21tm_TEVHAHA-tail-expressing U373 cells with anti-U21C or anti-HA, as noted. Positions of U21, class I MHC heavy chains (MHCI HC), and U21tm_TEVHAHA-tail (U21HA) are noted. (c) Immunoblot of U373 or U21- or U21tm_TEVHAHA-tail-expressing U373 lysates with an anti-U21 C-terminal antibody. Migration positions of U21tm_TEVHAHA-tail and U21 are noted.