Tropomodulin 1-null mice have a mild spherocytic elliptocytosis with appearance of tropomodulin 3 in red blood cells and disruption of the membrane skeleton.

ABSTRACT: The short actin filaments in the red blood cell (RBC) membrane skeleton are capped at their pointed ends by tropomodulin 1 (Tmod1) and coated with tropomyosin (TM) along their length. Tmod1-TM control of actin filament length is hypothesized to regulate spectrin-actin lattice organization and membrane stability. We used a Tmod1 knockout mouse to investigate the in vivo role of Tmod1 in the RBC membrane skeleton. Western blots of Tmod1-null RBCs confirm the absence of Tmod1 and show the presence of Tmod3, which is normally not present in RBCs. Tmod3 is present at only one-fifth levels of Tmod1 present on wild-type membranes, but levels of actin, TMs, adducins, and other membrane skeleton proteins remain unchanged. Electron microscopy shows that actin filament lengths are more variable with

SUBMITTER: Moyer JD 

PROVIDER: S-EPMC2953891 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature