IMMUNOCYTOCHEMICAL LOCALIZATION OF CYCLIC-GMP, CGMP-DEPENDENT PROTEIN-KINASE, CALMODULIN AND CALCINEURIN IN PARAMECIUM TETRAURELIA

  • 1 January 1983
    • journal article
    • research article
    • Vol. 32  (1) , 164-170
Abstract
The localization of cGMP, cGMP-dependent protein kinase, calmodulin and the calmodulin-binding protein calcineurin in P. tetraurelia cells was examined with immunocytochemical methods. These molecules appeared to be localized to a large extent in the cilia of this protozoan. To ascertain that antibodies had access to all cellular compartments 3 different preparations were used for immunocytochemistry: with whole cell preparations immunofluorescent staining for the 4 molecules was mainly visible in the cilia; in deciliated Paramecium, staining for cGMP and calmodulin was found in regular patterns on the cell surface most likely representing kinetosomes; using sectioned cells, additional cytoplasmic calmodulin appeared to be associated with glycogen particles as evidenced by the disapperance of the granular staining pattern after preincubation with .alpha.-amylase. In contrast, cGMP, cGMP-dependent protein kinase and calcineurin fluorescence was only very weak and diffuse in cell bodies. No nuclear fluorescence was detectable after staining with any of the antibodies. Because of the colocalization of cGMP, cGMP-dependent protein kinase, a guanylate cyclase-calmodulin-complex and calcineurin in cilia from Paramecium, an involvement of these components in the regulation of ciliary activity is discussed.