240 kDa immunoanalogue of vertebrate α‐spectrin occurs in Paramecium cells

Abstract

AbstractPolypeptide of 240 kDa immunorelated to vertebrate α‐spectrin was detected in Paramecium cells. The antigen was identified by monospecific antibody directed against α‐subunit of spectrin, which was isolated from chicken erythrocytes by affinity and anion‐exchange chromatography. Immunoblotting tests demonstrated that the anti‐α‐spectrin cross reacted with the 240 kDa polypeptide of Paramecium as well as that of various vertebrate cells. In Paramecium, the antigen was detected in cytoskeletal fraction and in contractile extract of the cells. Immuno‐fluorescent and immunoelectron microscopy observations revealed cortical localization of α‐spectrin immunoanalogue in Paramecium. The label was distinctly seen on the whole surface of trichocyst tips. The antigen was also distributed close to the inner alveolar membrane forming a regular, continuous, lattice‐like structure. When stained with rhodamine‐phalloidin, Paramecium cells displayed a similar fluorescent network, which underlay contours of cortical units. Basal bodies of cilia were labeled with phalloidin as well. Detection of α‐spectrin immunoanalogue in Paramecium cortex may provide a new insight into arrangement of cortical elements in this organism. © 1992 Wiley‐Liss, Inc.