Biosynthesis of granulysin, a novel cytolytic molecule

Mol Immunol. 1999 May;36(7):413-22. doi: 10.1016/s0161-5890(99)00063-2.

Abstract

Granulysin is a newly described lytic molecule expressed by CTL and NK cells. Three mRNA (519, 520, and 522) and two protein products of 15 and 9 kDa are encoded by the granulysin gene. Stable transfectants overexpressing the predominate 520 mRNA were generated to determine the protein products originating from the translation of this message. A transfectant of the NK cell tumor YT overexpressed both 15 and 9 kDa proteins while a transfectant of the T cell tumor HuT78 produced mainly 15 kDa granulysin. Thus the 520 mRNA is sufficient for production of both 15 and 9 kDa granulysin. 9 kDa granulysin accumulated via post-translational processing of 15 kDa protein and was present intracellularly but not in the cell culture supernatant, indicating specific retention of the 9 kDa protein. An inhibitor of granule acidification, concanamycin A, blocked the processing of 15 kDa granulysin to the 9 kDa form. A deduced structural difference between the two forms of the protein and a decrease in lytic activity of 9 kDa granulysin at granule pH suggest two mechanisms by which a granulysin expressing cell is protected from autolysis during the biosynthesis of this potentially harmful molecule.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Antigens, Differentiation, T-Lymphocyte / biosynthesis*
  • Antigens, Differentiation, T-Lymphocyte / chemistry
  • Antigens, Differentiation, T-Lymphocyte / immunology
  • Antigens, Differentiation, T-Lymphocyte / metabolism
  • Dose-Response Relationship, Drug
  • Enzyme Inhibitors
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Hydrogen-Ion Concentration
  • Killer Cells, Natural / chemistry*
  • Killer Cells, Natural / immunology
  • Kinetics
  • Macrolides*
  • Precipitin Tests
  • T-Lymphocytes, Cytotoxic / chemistry*
  • T-Lymphocytes, Cytotoxic / immunology
  • Transfection
  • Tumor Cells, Cultured

Substances

  • Anti-Bacterial Agents
  • Antigens, Differentiation, T-Lymphocyte
  • Enzyme Inhibitors
  • GNLY protein, human
  • Macrolides
  • concanamycin A