The cytoskeleton of digestive epithelia in health and disease

The mammalian cell cytoskeleton consists of a diverse group of fibrillar el ements that play a pivotal role in mediating a number of digestive and nond igestive cell functions, including secretion, absorption, motility, mechani cal integrity, and mitosis. The cytoskeleton of higher-eukaryotic cells con sists of three highly abundant major protein families: microfilaments (MF), microtubules (MT), and intermediate filaments (IF), as well as a growing n umber of associated proteins. Within digestive epithelia, the prototype mem bers of these three protein families are actins, tubulins, and keratins, re spectively. This review highlights the important structural, regulatory, fu nctional, and unique features of the three major cytoskeletal protein group s in digestive epithelia. The emerging exciting biological aspects of these protein groups are their involvement in cell signaling via direct or indir ect interaction with a growing list of associated proteins (MF, MT, IF), th e identification of several disease-causing mutations (IF, MF), the functio nal role that they play in protection from environmental stresses (IF), and their functional integration via several linker proteins that bridge two o r potentially ail three of these groups together. The use of agents that ta rget specific cytoskeletal elements as therapeutic modalities for digestive diseases offers potential unique areas of intervention that remain to be f ully explored.