| First Author | Toivola DM | Year | 2004 |
| Journal | J Cell Biol | Volume | 164 |
| Issue | 6 | Pages | 911-21 |
| PubMed ID | 15007064 | Mgi Jnum | J:89299 |
| Mgi Id | MGI:3039339 | Doi | 10.1083/jcb.200308103 |
| Citation | Toivola DM, et al. (2004) Keratins modulate colonocyte electrolyte transport via protein mistargeting. J Cell Biol 164(6):911-21 |
| abstractText | 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. |
