Claudins - general

Topic Completed: 1 July 2013

Minor changes: 31 August 2020

Copyright: 2003-2020,, Inc.

PubMed Search: claudins

Nat Pernick, M.D.
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Cite this page: Pernick N. Claudins - general. website. Accessed September 20th, 2020.
Definition / general
  • Multigene family of integral membrane proteins active in tight junction formation and function
  • Most claudin genes appear decreased in cancer, while CLDN3, CLDN4 and CLDN7 are elevated in several malignancies (BMC Cancer 2006;6:186)
  • Tight junctions (zonula occludens) form continuous barrier to fluids across epithelium and endothelium; regulate paracellular permeability and maintain cell polarity by blocking movement of transmembrane proteins between apical and basolateral cell surfaces (Annu Rev Cell Dev Biol 2006;22:207)
  • Tight junctions are composed of claudin and occludin proteins, which join the junctions to the cytoskeleton
  • Claudin family has > 20 integral membrane proteins, expressed in tissue specific pattern that may determine strength and properties of epithelial barrier; usually cells from a specific organ express multiple claudin proteins
Positive staining - normal
  • Epithelial and endothelial cells
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