Two Drosophila nervous system antigens, Nervana 1 and 2, are homologous to the beta subunit of Na+,K(+)-ATPase.

Abstract

A nervous system-specific glycoprotein antigen from adult Drosophila heads, designated Nervana (Nrv), has been purified on the basis of reactivity of its carbohydrate epitope(s) with anti-horseradish peroxidase (HRP) antibodies that are speciflc markers for Drosophila neurons. Anti-Nrv monoclonal antibodies (mAbs), specific for the protein moiety of Nrv, were used to screen a Drosophila embryo cDNA expression library. Three cDNA clones (designated Nrvl, Nrv2.1, and Nrv2.2) were isolated that code for proteins recognized by anti-Nrv mAbs on Western blots. DNA sequencing and Southern blot analyses established that the cDNA clones are derived from two different genes. In situ hybridization to Drosophila polytene chromosomes showed that the cDNA clones map to the third chromosome near 92C-D. Nrvl and Nrv2.1/2.2 have open reading frames of 309 and 322/323 amino acids, respectively, and they are 43.4% identical at the amino acid level. The proteins deduced from these clones exhibit significant homology in both primary sequence and predicted topology to the j3 subunit of Na+,K+-ATPase. Immunoaffinity-purified Nrv is associated with a protein (Mr 100,000) recognized on Western blots by anti-ATPase a-subunit mAb. Our results suggest that the Drosophila nervous system-specific antigens Nrvl and -2 are neuronal forms of the f subunit of Na+,K+-ATPase.

Traffic of Dynamin within IndividualDrosophilaSynaptic Boutons Relative to Compartment-Specific Markers

“…Immunoelectron microscopy has been used to show that this epitope is highly enriched on insect neuronal cell surface (Sabry et al, 1991). In Western blots, the axonal protein most strongly labeled by anti-HRP is a membraneand cytoskeleton-associated ␤ subunit of the Na ϩ /K ϩ ATPase (Sun and Salvaterra, 1995;van de Goor et al, 1995). We have shown previously by optical microscopy that the csp seems to redistribute in synaptic vesicle-depleted shi ts1 terminals from an intracellular compartment surrounded by anti-HRP immunoreactivity to a compartment indistinguishable from plasma membrane (Ramaswami et al, 1994;van de Goor et al, 1995).…”

The Na+/K+ ATPase is required for septate junction function and epithelial tube-size control in theDrosophilatracheal system

“…UAS-nrv1, UAS-nrv2.1, UAS-nrv2.2 and UASnrv3 were constructed by inserting nrv1, nrv2.1, nrv2.2 (Sun and Salvaterra, 1995b) and nrv3 cDNAs into the pUAST vector (Brand and Perrimon, 1993). nrv2 alleles were sequenced by PCR amplification of genomic DNA from heterozygous flies, followed by cycle dye termination sequencing.…”

“…There are two α subunit loci, ATPα that produces at least 12 α subunit isoforms (Palladino et al, 2003), and CG17923, which appears to be minimally expressed because its transcripts are poorly represented in existing cDNA libraries. Of these loci, only nrv1, nrv2 and ATPα have been characterized in detail, primarily for their roles in the nervous system (Lebovitz et al, 1989;Palladino et al, 2003;Sun and Salvaterra, 1995b;Sun et al, 1998). A tracheal phenotype was recently described for ATPα mutants, although β-subunit mutants were not analyzed (Hemphala et al, 2003).…”

Genetic Interaction of Lobe With Its Modifiers in Dorsoventral Patterning and Growth of the Drosophila Eye

“…EP2454, an insertion in the nervana 1 (nrv 1) gene that encodes a subunit of sodium/potassium ATPase (Sun and Salvaterra 1995), rescued the ventral eye loss of the L 2 /1 mutant in the eye disc ( Figure 2Q) and the adult eye ( Figure 2R). ey.nrv 1 in a wild-type background did not affect eye size ( Figure 2P).…”

“…We also identified genes involved in cell survival and growth such as disc over grown (dco), a member of the serine/threonine protein kinases family (Kloss et al 1998), and genes involved in vesicular trafficking, including RhoGAP68F, an ion transport such as nrv 1 (Sun and Salvaterra 1995), and the acetyl transferase nej (Kumar et al 2004). It is possible that potential DV asymmetric function of these genes might have been missed by LOF analysis because of functional redundancy or these genes may be modifying the early growth function of L in the eye.…”