Co-distribution of glycoconjugates and H(+), K(+)-ATPase in the parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum (Schreber, 1774).
Histochemical, lectin-histochemical, and immunohistochemical analyses were performed on parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum, to clarify the composition and distribution of oligosaccharide chains in the beta-subunit of the protonic pump H(+),K(+)-ATPase. PAS, Alcian Blue (pH 2.5) and Alcian Blue (pH 1.0) stainings detected only neutral glycoconjugates. Lectin-binding analyses included LTA, UEA-I, ConA, SBA, BSI-B4, AAA, DBA, PNA, and WGA. WGA-and PNA-bindings were also tested after beta-elimination to detect O-linked glycans. Parietal cells were negative for binding to LTA and UEA-I, and to PNA and WGA after beta-elimination, indicating the lack of (1,2) fucosylated residues and of N-linked glycans, respectively. Immunohistochemical tests with anti-alpha- and anti-beta-H(+),K(+)-ATPase were positive. Two alternative patterns of glycoconjugate distribution were found, i.e. a perinuclear and a diffuse one, indicating localization in the intracellular canaliculus and in the tubulovesicular system of the parietal cells, respectively. Both the subunits of the H(+),K(+)-ATPase and the galactosyl/galactosaminyl residues were co-distributed in both the perinuclear and the diffuse patterns, suggesting that the residues are part of the protonic pump. Glycosyl/glycosaminyl and mannosyl groups were concentrated in the tubulovesicular system, and fucosylated residues were found almost exclusively in the intracellular canaliculi; thus they are probably not included in the oligosaccharide chains of beta-H(+),K(+)-ATPase. These findings indicate that the oligosaccharide chains linked to the beta-H(+),K(+)-ATPase subunit in R. ferrumequinum have distinct features compared to the other mammals studied and confirms the taxon specificity of the chains in the proton pump.
Scillitani
Giovanni
G
Dipartimento di Biologia Animale ed Ambientale, Université degli Studi di Bari, via Orabona 4/a, I-70125 Bari, Italy. g.scillitani@biologia.uniba.it
Mastrodonato
Maria
M
Liquori
Giuseppa Esterina
GE
Ferri
Domenico
D
D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D005260:Female; D006001:Glycoconjugates / Q000378:metabolism*; D017506:H(+)-K(+)-Exchanging ATPase / Q000378:metabolism*; D008297:Male; D010295:Parietal Cells, Gastric / Q000166:cytology / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*
D006001:Glycoconjugates; D017506:H(+)-K(+)-Exchanging ATPase