Mucus Detachment by Host Metalloprotease Meprin beta Requires Shedding of Its Inactive Pro-form, which Is Abrogated by the Pathogenic Protease RgpB

• The host metalloprotease meprin beta is required for mucin 2 (MUC2) cleavage, which drives intestinal mucus detachment and prevents bacterial over-growth. To gain access to the cleavage site in MUC2, meprin b must be proteolytically shed from epithelial cells. Hence, regulation of meprin b shedding and activation is important for physiological and pathophysiological conditions. Here, we demonstrate that meprin b activation and shedding are mutually exclusive events. Employing ex vivo small intestinal organoid and cell culture experiments, we found that ADAM-mediated shedding is restricted to the inactive pro-form of meprin beta and is completely inhibited upon its conversion to the active form at the cell surface. This strict regulation of meprin beta activity can be overridden by pathogens, as demonstrated for the bacterial protease Arg-gingipain (RgpB). This secreted cysteine protease potently converts membrane-bound meprin beta into its active form, impairing meprin beta shedding and its function as a mucus-detaching protease.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)

Nyckelord

aminobenzoic acid hydrolase

inflammatory-bowel-disease

functional cftr

channel

cystic-fibrosis mucus

cell-cell adhesion

porphyromonas-gingivalis

targeted disruption

epithelial-cells

small-intestine

alpha-subunit

Publikations- och innehållstyp

ref (ämneskategori)

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