Protein 4.1R stabilizes the red-blood-cell membrane by anchoring integral membrane proteins to the spectrin-actin skeleton below. It is also present in nonerythroid cells at various subcellular locations. Isabel Correas and co-workers now reveal that here it regulates a very different component of the cytoskeleton: microtubules (see p. 6197). They find that expressing 4.1R in fibroblasts alters interphase microtubule architecture rather than the actin cytoskeleton. In addition, it disrupts centrosomes, causing the microtubule motor dynein to become displaced from these organelles. The authors then use confocal microscopy and western blotting to demonstrate that endogenous 4.1R can be identified in isolated centrosomes. Moreover, they show recombinant 4.1R localizes to the centre of microtubule asters produced in vitro and can promote their assembly. Correas and co-workers conclude that 4.1R plays a role at centrosomes in maintenance of the radial microtubule arrays that these organelles control. One possibility is that it also has an anchoring role in this part of the cell - tethering microtubules to centrosomes.
IN THIS ISSUE|
01 December 2004
4.1 drops actin' role for microtubules
Online ISSN: 1477-9137
Print ISSN: 0021-9533
© The Company of Biologists Limited
2004
J Cell Sci (2004) 117 (25): e2504.
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Protein 4.1R regulates interphase microtubule organization at the centrosome
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4.1 drops actin' role for microtubules. J Cell Sci 1 December 2004; 117 (25): e2504. doi:
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