Intragenic duplication: A novel mutational mechanism in hereditary pancreatitis

Maiken T. Joergensen, Andrea Geisz, Klaus Brusgaard, Ove B. Schaffalitzky De Muckadell, Péter Hegyi, Anne Marie Gerdes, Miklós Sahin-Tóth

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Objectives: In a hereditary pancreatitis family from Denmark, we identified a novel intragenic duplication of 9 nucleotides in exon-2 of the human cationic trypsinogen (PRSS1) gene (c.63-71dup) which at the amino-acid level resulted in the insertion of 3 amino acids within the activation peptide of cationic trypsinogen (p.K23-I24insIDK). The aim of the present study was to characterize the effect of this unique genetic alteration on the function of human cationic trypsinogen. Methods: Wild-type and mutant cationic trypsinogens were produced recombinantly and purified to homogeneity. Trypsinogen activation was followed by enzymatic assays and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Trypsinogen secretion was measured from transfected HEK 293T cells. Results: Recombinant cationic trypsinogen carrying the p.K23-I24insIDK mutation exhibited greater than 10-fold increased autoactivation. Activation by human cathepsin B also was accelerated by 10-fold. Secretion of the p.K23-I24insIDK mutant from transfected cells was diminished, consistent with intracellular autoactivation. Conclusions: This is the first report of an intragenic duplication within the PRSS1 gene causing hereditary pancreatitis. The accelerated activation of p.K23-I24insIDK by cathepsin B is a unique biochemical property not found in any other pancreatitis-associated trypsinogen mutant. In contrast, the robust autoactivation of the novel mutant confirms the notion that increased autoactivation is a disease-relevant mechanism in hereditary pancreatitis.

Original languageEnglish
Pages (from-to)540-546
Number of pages7
JournalPancreas
Volume40
Issue number4
DOIs
Publication statusPublished - May 1 2011

Keywords

  • Hereditary pancreatitis
  • PRSS1
  • autoactivation
  • cathepsin B
  • enteropeptidase
  • human cationic trypsinogen
  • intragenic duplication

ASJC Scopus subject areas

  • Internal Medicine
  • Endocrinology, Diabetes and Metabolism
  • Hepatology
  • Endocrinology

Fingerprint Dive into the research topics of 'Intragenic duplication: A novel mutational mechanism in hereditary pancreatitis'. Together they form a unique fingerprint.

  • Cite this

    Joergensen, M. T., Geisz, A., Brusgaard, K., Schaffalitzky De Muckadell, O. B., Hegyi, P., Gerdes, A. M., & Sahin-Tóth, M. (2011). Intragenic duplication: A novel mutational mechanism in hereditary pancreatitis. Pancreas, 40(4), 540-546. https://doi.org/10.1097/MPA.0b013e3182152fdf