4tpz
N-terminal domain of C. Reinhardtii SAS-6 homolog bld12p F145W (NN2)
Structural highlights
FunctionPublication Abstract from PubMedCentrioles are critical for the formation of centrosomes, cilia and flagella in eukaryotes. They are thought to assemble around a nine-fold symmetric cartwheel structure established by SAS-6 proteins. Here, we have engineered Chlamydomonas reinhardtii SAS-6-based oligomers with symmetries ranging from five- to ten-fold. Expression of a SAS-6 mutant that forms six-fold symmetric cartwheel structures in vitro resulted in cartwheels and centrioles with eight- or nine-fold symmetries in vivo. In combination with Bld10 mutants that weaken cartwheel-microtubule interactions, this SAS-6 mutant produced six- to eight-fold symmetric cartwheels. Concurrently, the microtubule wall maintained eight- and nine-fold symmetries. Expressing SAS-6 with analogous mutations in human cells resulted in nine-fold symmetric centrioles that exhibited impaired length and organization. Together, our data suggest that the self-assembly properties of SAS-6 instruct cartwheel symmetry, and lead us to propose a model in which the cartwheel and the microtubule wall assemble in an interdependent manner to establish the native architecture of centrioles. SAS-6 engineering reveals interdependence between cartwheel and microtubules in determining centriole architecture.,Hilbert M, Noga A, Frey D, Hamel V, Guichard P, Kraatz SH, Pfreundschuh M, Hosner S, Fluckiger I, Jaussi R, Wieser MM, Thieltges KM, Deupi X, Muller DJ, Kammerer RA, Gonczy P, Hirono M, Steinmetz MO Nat Cell Biol. 2016 Apr;18(4):393-403. doi: 10.1038/ncb3329. Epub 2016 Mar 21. PMID:26999736[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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