We studied the arrangement of the cross-filaments in intestinal microvilli to understand how microfilaments interact with the membrane. Observations on thin-sectioned or negatively stained microvilli with the electron microscope demonstrate that the cross-filaments on the core bundle lie opposite to one another and are spaced 32.5 nm apart. In sections grazing through the membranes, the cross-filaments appear as transverse stripes in a barber-polelike arrangement. The cross-filaments point away from the microvillus tip. This subfragments S1 or HMM. The cross filaments are associated not only with the microfilaments but also with electron-dense patches on the inside surface of the membrane. These results suggest the cross-filaments are arranged as a double helix around the core bundle. Furthermore, the cross-filaments can serve as in situ markers for microvillar polarity. Lastly, the cross-filaments interact not only with specific portions on the actin filaments but also with dense patches on the membrane. These observations are summarized in a model of the microvillus cytoskeleton.
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Article| March 01 1982
Organization of the cross-filaments in intestinal microvilli.
P T Matsudaira
D R Burgess
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1982) 92 (3): 657–664.
P T Matsudaira, D R Burgess; Organization of the cross-filaments in intestinal microvilli.. J Cell Biol 1 March 1982; 92 (3): 657–664. doi: https://doi.org/10.1083/jcb.92.3.657
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