Biosynthesis of granulysin, a novel cytolytic molecule

Related Experiment Video

Updated: Oct 19, 2026

A High Yield and Cost-efficient Expression System of Human Granzymes in Mammalian Cells
09:16

A High Yield and Cost-efficient Expression System of Human Granzymes in Mammalian Cells

Published on: June 10, 2015

D A Hanson1, A A Kaspar, F R Poulain

  • 1Department of Pediatrics, Stanford University School of Medicine, CA 94305-5208, USA.

Molecular Immunology
|August 17, 1999
PubMed

Insights

Granulysin, a cytotoxic molecule from CTL and NK cells, is produced in 15 and 9 kDa forms from the 520 mRNA. Processing of the 15 kDa form to 9 kDa is blocked by inhibiting granule acidification, protecting cells from self-damage.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • Granulysin is a cytotoxic molecule expressed by cytotoxic T lymphocytes (CTL) and Natural Killer (NK) cells.
  • The granulysin gene encodes three mRNA variants (519, 520, 522) and two protein products (15 kDa and 9 kDa).

Purpose of the Study:

  • To investigate the protein products derived from the predominant 520 mRNA of granulysin.
  • To elucidate the post-translational processing and cellular localization of granulysin protein forms.
  • To understand the mechanisms protecting cells from granulysin-mediated autolysis.

Main Methods:

  • Generation of stable transfectants overexpressing the 520 mRNA in YT (NK) and HuT78 (T) cell lines.
  • Analysis of protein expression and processing using Western blotting.
  • Investigation of the effect of granule acidification inhibitors (concanamycin A) on protein processing.

Main Results:

  • The 520 mRNA is sufficient for producing both 15 kDa and 9 kDa granulysin proteins.
  • YT cells produced both 15 and 9 kDa forms, while HuT78 cells primarily produced the 15 kDa form.
  • 9 kDa granulysin results from post-translational processing of the 15 kDa form and is retained intracellularly.
  • Inhibition of granule acidification blocked the conversion of 15 kDa to 9 kDa granulysin.
  • Structural differences and reduced lytic activity of 9 kDa granulysin at acidic pH suggest autoprotective mechanisms.

Conclusions:

  • The 520 mRNA variant of granulysin can generate both 15 kDa and 9 kDa protein products.
  • Intracellular processing and retention of the 9 kDa form, influenced by granule pH, protect expressing cells from autolysis.
  • Granulysin biosynthesis involves self-protection mechanisms to prevent damage to the producing cytotoxic cells.

More Related Videos

A Colorimetric Assay that Specifically Measures Granzyme B Proteolytic Activity: Hydrolysis of Boc-Ala-Ala-Asp-S-Bzl05:20

A Colorimetric Assay that Specifically Measures Granzyme B Proteolytic Activity: Hydrolysis of Boc-Ala-Ala-Asp-S-Bzl

Published on: November 28, 2014

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth09:10

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth

Published on: January 7, 2022

Related Concept Videos

Inhibitors of Gram-positive Cell Wall Synthesis01:23

Inhibitors of Gram-positive Cell Wall Synthesis

Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...
Inhibitors of Bacterial Protein Synthesis01:25

Inhibitors of Bacterial Protein Synthesis

Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
Overview of Secretory Vesicles01:33

Overview of Secretory Vesicles

Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Proteoglycans01:05

Proteoglycans

Glycans, a class of complex heterogeneous molecules, can be covalently attached to proteins to form glycosylated proteins that regulate various physiological and pathological processes. Glycosylated proteins or glycoproteins comprise N-linked and O-linked oligosaccharides. O-glycosylation is the most common type of protein glycosylation. Here, glycans attach to the oxygen atom of the hydroxyl groups of Serine or Threonine residues. O-linked glycosylation occurs later in protein processing,...