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Acta Biologica Hungarica

, Volume 52, Issue 4, pp 473–484 | Cite as

The Immunoprotein Scolexin and Its Synthesizing Sites — The Midgut Epithelium and the Epidermis

  • Kinga MolnárEmail author
  • Noemi H. Borhegyi
  • Gy. Csikós
  • M. Sass
Article

Abstract

Scolexin is one of the bacterial induced hemolymph proteins of tobacco hornworm (Manduca sexta) larvae, that has hemocyte coagulation-provoking activity. The 72 kDa scolexin complex is composed of two 36 kDa subunits. To examine the protein secretory pathways in insect epithelia a polyclonal antibody was raised against the 36 kDa hemolymph protein. This MsH36 antibody recognised a 36 and a 72 kDa protein in tissue homogenates. On the basis of the characteristic labelling pattern observed on immunoblots and immunocytochemical sections we concluded that the 36 kDa protein in the hemolymph, in the midgut and in the epidermis was identical with the scolexin subunit. In present paper we report a labelling shift in the midgut epithelium between goblet and columnar cells that may be controlled by the hormonal system. A 72 kDa protein showed similar epitops and molecular weight to the scolexin complex and was detected in epidermis and in cuticle under both reducing and non-reducing conditions. Tissue localization of 36 kDa and 72 kDa MsH36 antibody labelling proteins indicated the possibility that the epidermal cells produce two kinds of scolexin-like proteins. The complex composed of 36 kDa subunits are transported basolaterally into the circulation and display hemocyte coagulation inducing activity while the 72 kDa form contains two subunits linked covalently secreted apically into the cuticle.

Keywords

Scolexin secretory pathway midgut epidermis cuticle 

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© Akadémiai Kiadó, Budapest 2001

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • Kinga Molnár
    • 1
    Email author
  • Noemi H. Borhegyi
    • 1
  • Gy. Csikós
    • 1
  • M. Sass
    • 1
  1. 1.Department of General ZoologyEötvös Loránd UniversityBudapestHungary

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