Keratins modulate colonocyte electrolyte transport via protein mistargeting

Diana Toivola, S Krishnan, HJ Binder, SK Singh, MB Omary

Research output: Contribution to journalArticleScientificpeer-review

101 Citations (Scopus)

Abstract

The function of intestinal keratins is unknown, although keratin 8 (K8)-null mice develop colitis, hyperplasia, diarrhea, and mistarget jejunal apical markers. We quantified the diarrhea in K8-null stool and examined its physiologic basis. Isolated crypt-units from K8-null and wild-type mice have similar viability. K8-null distal colon has normal tight junction permeability and paracellular transport but shows decreased short circuit current and net Na absorption associated with net Cl secretion, blunted intracellular Cl/HCO3-dependent pH regulation, hyperproliferation and enlarged goblet cells, partial loss of the membrane-proximal markers H,K-ATPase-beta and F-actin, increased and redistributed basolateral anion exchanger AE1/2 protein, and redistributed Na-transporter ENaC-gamma. Diarrhea and protein mistargeting are observed 1-2 d after birth while hyperproliferation/inflammation occurs later. The AE1/2 changes and altered intracellular pH regulation likely account, at least in part, for the ion transport defects and hyperproliferation. Therefore, colonic keratins have a novel function in regulating electrolyte transport, likely by targeting ion transporters to their cellular compartments.
Original languageUndefined/Unknown
Pages (from-to)911–921
Number of pages11
JournalJournal of Cell Biology
Volume164
Issue number6
DOIs
Publication statusPublished - 2004
MoE publication typeA1 Journal article-refereed

Keywords

  • diarrhea
  • intermediate filaments
  • Intestine

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