Molecular characterization and immunohistochemical localization of palmdelphin, a cytosolic isoform of the paralemmin protein family implicated in membrane dynamics.
Palmdelphin is a newly identified cytosolic isoform of paralemmin-1, a lipid raft-associated protein implicated in cell shape control. Like paralemmin-1, palmdelphin is phosphorylated, giving rise to electrophoretic band heterogeneity that is most pronounced in the brain. In ultracentrifugation and gel filtration palmdelphin behaves as a non-globular monomer. Its C-terminal region binds glutamine synthetase. Immunohistochemical analysis of the rat brain shows a prominent localization of palmdelphin in the cerebral cortex, hippocampus, amygdala, septum, indusium griseum, piriform cortex, nucleus supraopticus, and nucleus of the lateral olfactory tract. Many of the circumscript palmdelphin-positive areas are related to the olfactory system. Immunoperoxidase electron microscopy reveals a discontinuous distribution of palmdelphin immunoreactivity, in the form of spots scattered throughout the cytoplasm of selected neuronal perikarya and dendrites, including dendritic spines, often in association with endomembranes, and in a pattern which is similar to that of the cytoplasmic fraction of paralemmin-1. In subcellular fractionation experiments palmdelphin behaves as a cytosolic protein which, however, can be partially recruited from cytosol to the detergent-resistant fraction of a membrane/cytoskeletal cell ghost preparation. These observations suggest that palmdelphin may peripherally associate with endomembranes or cytoskeleton-linked structures.
Hu
Bin
B
Institut für Physiologische Chemie, Ruhr-Universität Bochum, Germany.
Petrasch-Parwez
Elisabeth
E
Laue
Michael M
MM
Kilimann
Manfred W
MW
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002462:Cell Membrane / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003600:Cytosol / Q000737:chemistry*; D016650:Fluorescein-5-isothiocyanate; D019084:Fluorescent Antibody Technique, Indirect; D005456:Fluorescent Dyes; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009195:Peroxidase / Q000378:metabolism / Q000648:ultrastructure; D010766:Phosphorylation; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
D005456:Fluorescent Dyes; D008565:Membrane Proteins; C434124:Palmd protein, mouse; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D009195:Peroxidase; D005982:Glutathione Transferase; D005974:Glutamate-Ammonia Ligase; D016650:Fluorescein-5-isothiocyanate