Tmod3 is associated with RBC membranes (Mg⁺⁺ ghosts) and Triton-insoluble membrane skeletons from Tmod1-null mice. (A) Coomassie blue–stained sodium dodecylsulfate–polyacrylamide gel electrophoresis (SDS-PAGE) of ghosts and Triton-insoluble membrane skeletons showing no alterations in major membrane proteins in the absence of Tmod1. (B) Western blots showing Tmod3 in ghosts from Tmod1-null (Tmod1^−/−Tg+) but not wild-type (Tmod1^+/+Tg+ and Tmod1^+/+) or heterozygous (Tmod1^−/+Tg+ and Tmod1^−/+) mice. Levels of Tmod1 in ghosts from wild-type and heterozygous mice are similar regardless of the presence of the α-MHC-Tmod1 transgene (Tg⁺). Each lane in panels A and B is from a different individual animal. Equivalent ghost volumes were loaded to compare relative amounts of proteins. (C) Coomassie blue–stained gels and Western blots showing antibody specificities for Tmod1 or Tmod3. (D) Ratios of spectrin, band 4.1R, and actin to band 3 determined by densitometry from Coomassie blue–stained gels as in panel A. Data from wild-type and heterozygous animals were pooled (+/+) becauseTmod1 levels are the same in both genotypes (n = 9 for ghosts; n = 6 for skeletons). For Tmod1-nulls (−/−), n = 7 for ghosts; n = 6 for skeletons. Differences between +/+ and −/− datasets were not significantly different.