First Author | Revenu C | Year | 2012 |
Journal | Mol Biol Cell | Volume | 23 |
Issue | 2 | Pages | 324-36 |
PubMed ID | 22114352 | Mgi Jnum | J:219622 |
Mgi Id | MGI:5621262 | Doi | 10.1091/mbc.E11-09-0765 |
Citation | Revenu C, et al. (2012) A new role for the architecture of microvillar actin bundles in apical retention of membrane proteins. Mol Biol Cell 23(2):324-36 |
abstractText | Actin-bundling proteins are identified as key players in the morphogenesis of thin membrane protrusions. Until now, functional redundancy among the actin-bundling proteins villin, espin, and plastin-1 has prevented definitive conclusions regarding their role in intestinal microvilli. We report that triple knockout mice lacking these microvillar actin-bundling proteins suffer from growth delay but surprisingly still develop microvilli. However, the microvillar actin filaments are sparse and lack the characteristic organization of bundles. This correlates with a highly inefficient apical retention of enzymes and transporters that accumulate in subapical endocytic compartments. Myosin-1a, a motor involved in the anchorage of membrane proteins in microvilli, is also mislocalized. These findings illustrate, in vivo, a precise role for local actin filament architecture in the stabilization of apical cargoes into microvilli. Hence, the function of actin-bundling proteins is not to enable microvillar protrusion, as has been assumed, but to confer the appropriate actin organization for the apical retention of proteins essential for normal intestinal physiology. |