A gene family consisting of ezrin, radixin and moesin. Its specific localization at actin filament/plasma membrane association sites.
Radixin is a barbed end-capping actin-modulating protein which was previously reported to be concentrated at cell-to-cell adherens junctions (AJ) and cleavage furrows. Recently, cDNA encoding mouse radixin was isolated, showing that radixin is highly homologous to but distinct from ezrin. From mouse teratocarcinoma cells we isolated and analyzed cDNA encoding another radixin-related protein. Sequence analysis has demonstrated that this protein is a mouse homologue of human moesin (98.3% identity) and that it shares 71.7% and 80.1% identity with ezrin and radixin, respectively. Translation experiments in vitro combined with immunoblot analyses led us to conclude that there is a gene family consisting of ezrin, radixin and moesin. These members are coexpressed in various types of cells. Then, by immunofluorescence microscopy, we closely analyzed their distribution using polyclonal and monoclonal antibodies, which could recognize all three members. In addition to cell-to-cell AJ and cleavage furrows, it was shown that they were concentrated at microvilli and ruffling membranes in various types of cells. Furthermore, the cell-to-substrate AJ (focal contacts) were clearly stained by anti-radixin pAb only after the apical/lateral membranes and cytoplasm were removed by the zinc method. We conclude that at least one of the members of the ezrin-radixin-moesin family is concentrated at specific regions where actin filaments are densely associated with plasma membranes.
Sato
N
N
Department of Information Physiology, National Institute for Physiological Sciences, Aichi, Japan.
Funayama
N
N
Nagafuchi
A
A
Yonemura
S
S
Tsukita
S
S
Tsukita
S
S
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003598:Cytoskeletal Proteins; D004247:DNA / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D007365:Intercellular Junctions / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008840:Microfilament Proteins; D008871:Microvilli / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D000099149:Ezrin
D000199:Actins; D001798:Blood Proteins; D003598:Cytoskeletal Proteins; D004247:DNA; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D011506:Proteins; D000099149:Ezrin; C071058:moesin; C071776:radixin