Terminal differentiation in epithelia: the role of integrins in hensin polymerization

Q Al-Awqati - Annual Review of Physiology, 2011 - annualreviews.org
Annual Review of Physiology, 2011annualreviews.org
Epithelia, the most abundant cell type, differentiate to protoepithelia from stem cells by
developing apical and basolateral membrane domains and form sheets of cells connected
by junctions. Following this differentiation step, the cells undergo a second step (terminal
differentiation), during which they acquire a mature phenotype, which unlike the
protoepithelial one is tissue and organ specific. An extracellular matrix (ECM) protein termed
hensin (DMBT1) mediates this differentiation step in the kidney intercalated cells. Although …
Epithelia, the most abundant cell type, differentiate to protoepithelia from stem cells by developing apical and basolateral membrane domains and form sheets of cells connected by junctions. Following this differentiation step, the cells undergo a second step (terminal differentiation), during which they acquire a mature phenotype, which unlike the protoepithelial one is tissue and organ specific. An extracellular matrix (ECM) protein termed hensin (DMBT1) mediates this differentiation step in the kidney intercalated cells. Although hensin is secreted as a soluble monomer, it requires polymerization and deposition in the ECM to become active. The polymerization step is mediated by the activation of inside-out signaling by integrins and by the secretion of two proteins: cypA (a cis-trans prolyl isomerase) and galectin 3.
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