title: Immunochemical characterization and developmental expression of Shaker potassium channels from the nervous system of Drosophila.
abstract: We have raised antisera against recombinant peptides expressed from cDNAs fragments common to all splicing variants generated at the Shaker locus of Drosophila and used them as a tool to biochemically characterize these channel proteins. This antisera succeeded in detecting the expression of multiple Shaker potassium channels (Sh Kch), proteins with variable molecular mass (65-85 kDa) and pI (5.5-7). Additionally, for first time, specific Sh proteins of 40-45 kDa most probably corresponding to some of the so-called short Sh cDNAs previously isolated by others have been identified. Using genetic criteria, it has been determined that at least a good part of this variety of proteins is generated by alternative splicing. Developmental experiments show a double wave of Sh Kch channel expression with a first pick at the third instar larvae stage, a minimum at the beginning of puparation, and the highest plateau 36 h after hatching of adult flies. The pattern of Sh splice variants changes dramatically throughout development. A detergent-resistant fraction with about 50% of Sh Kch which seems to be anchored to submembranous structures has been found. Finally, other biochemical properties of Sh Kch, like membrane fractionation and glycosylation, are also described.
authors.affiliation: Instituto Cajal, Consejo Superior de Investigaciones Cietificas Madrid, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Rogero
authors.forename: F J
authors.initials: FJ
authors.lastname: Tejedor
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D015153:Blotting, Western; D002458:Cell Fractionation; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D015870:Gene Expression; D014644:Genetic Variation; D006023:Glycoproteins / Q000378:metabolism; D006257:Head; D007814:Larva; D008566:Membranes / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure; D009420:Nervous System / Q000196:embryology*; D009474:Neurons / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure; D017830:Octoxynol; D010446:Peptide Fragments / Q000276:immunology; D015221:Potassium Channels / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D011679:Pupa; D011994:Recombinant Proteins / Q000276:immunology; D051637:Shaker Superfamily of Potassium Channels; D013909:Thorax; D014018:Tissue Distribution
chemical_list: D018076:DNA, Complementary; D029721:Drosophila Proteins; D006023:Glycoproteins; D010446:Peptide Fragments; D015221:Potassium Channels; D011994:Recombinant Proteins; C496929:Sh protein, Drosophila; D051637:Shaker Superfamily of Potassium Channels; D017830:Octoxynol