Concentration of an integral membrane protein, CD43 (leukosialin, sialophorin), in the cleavage furrow through the interaction of its cytoplasmic domain with actin-based cytoskeletons.

Abstract

Abstract. In leukocytes such as thymocytes and basophilic leukemia cells, a glycosilated integral membrane protein called CIM3 (leukosialin or sialophorin), which is defective in patients with WiskottAldrich syndrome, was highly concentrated in the cleavage furrow during cytokinesis. Not only at the mitotic phase but also at interphase, CIM3 was precisely colocalized with ezrin-radixin-moesin family members (ERM), which were previously reported to play an important role in the plasma membrane-actin filament association in general. At the electron microscopic level, throughout the cell cycle, both CIM3 and ERM were tightly associated with microvilli, providing membrane attachment sites for actin filaments. We constructed a cDNA encoding a chimeric molecule consisting of the extracellular domain of mouse E-cadherin and the transmembrane/cytoplasmic domain of rat CD43, and introduced it into mouse L fibroblasts lacking both endogenous CD43 and E-cadherin. In dividing transfectants, the chimeric molecules were concentrated in the cleavage furrow together with ERM, and both proteins were precisely colocalized throughout the cell cycle. Furthermore, using this transfection system, we narrowed down the domain responsible for the CD43-concentration in the cleavage furrow. Based on these findings, we conclude that CD43 is concentrated in the cleavage furrow through the direct or indirect interaction of its cytoplasmic domain with ERM and actin filaments.

Reorganization of the human neutrophil plasma membrane is associated with functional priming: implications for neutrophil preparations

“…The morphological changes that occur in gelatin neutrophils during priming are consistent with and are in fact suggestive of the large-scale changes in membrane cortical organization observed in this study. Our approach to examining submembrane architecture was based on mapping the subcellular distribution of components contributing to the two major anchoring complexes that exist in hematopoietic cell plasma membranes, including the CD43-ezrin-F-actin [44,45] complex and CD45-fodrin complex [33]. CD43 is the major transmembrane sialoglycoprotein species in leukocytes and analogous to erythrocyte glycophorin C. Both proteins anchor to F-actin through Protein 4.l-like linkages (Band 4.1 in erythrocytes, ezrin in leukocytes).…”

Rho GTPase activity zones and transient contractile arrays

“…Accumulation of active Rho might activate PIP kinase, (63) thereby promoting the observed accumulation of active PIP2 in the furrow. (64,65) The PIP2 could then act as a GDF to liberate Rho from the GDI-Rho-GDP complex (see above). Accumulated PIP2 could also promote recruitment of ERM proteins such as radixin, which localize to cytokinetic furrows (66) and act as GDFs (see above).…”

Fly division.

“…However, a proper search for such phenotypes has not been performed. Vertebrate furrows also contain radixin, a member of the MER family, but this membrane-cytoskeletal linker appears in the cleavage furrow due to its association with microvilli in the furrow and not the contractile ring per se (Yonemura et al, 1993). A fly MER-like protein has been identified that is similar to all three of the vertebrate proteins (Edwards et al, 1994;McCartney, B., and R. Fehon, personal communication).…”