Last time, I heard Peter talked about his BBSome while I was still in Lineberger Cancer Center (UNC) and his work on BBSome has just published.
Cell. 2007 Jun 15;129(6):1201-13.
A core complex of BBS proteins cooperates with the GTPase Rab8 to promote ciliary membrane biogenesis.
Nachury MV, Loktev AV, Zhang Q, Westlake CJ, Peränen J, Merdes A, Slusarski DC, Scheller RH, Bazan JF, Sheffield VC, Jackson PK.
Genentech, Inc., South San Francisco, CA 94080, USA. firstname.lastname@example.org
Primary cilium dysfunction underlies the pathogenesis of Bardet-Biedl syndrome (BBS), a genetic disorder whose symptoms include obesity, retinal degeneration, and nephropathy. However, despite the identification of 12 BBS genes, the molecular basis of BBS remains elusive. Here we identify a complex composed of seven highly conserved BBS proteins. This complex, the BBSome, localizes to nonmembranous centriolar satellites in the cytoplasm but also to the membrane of the cilium. Interestingly, the BBSome is required for ciliogenesis but is dispensable for centriolar satellite function. This ciliogenic function is mediated in part by the Rab8 GDP/GTP exchange factor, which localizes to the basal body and contacts the BBSome. Strikingly, Rab8(GTP) enters the primary cilium and promotes extension of the ciliary membrane. Conversely, preventing Rab8(GTP) production blocks ciliation in cells and yields characteristic BBS phenotypes in zebrafish. Our data reveal that BBS may be caused by defects in vesicular transport to the cilium.
Today, in Gladstone, he further explained the mechanism of Rab8 in regulating ciliary membrane biogenesis, and also extended his LAP-based proteomics analysis approach to ciliopathies.
If you are interested the record video of this talk, please ask Peter directly to obtain it.
New in 'Theory'
- A clustering-outgrowth model for filopodia formation, based on study using Xenopus egg extracts and liposome
- Xenogeneic organ complementation is achievable! What's next? Human-pig chimera?
- Septins, planar cell polarity, cilia, convergent extension ... Bardet-Biedl and Meckel-Gruber syndromes
- Early-passage iPSCs retain cell-of-origin epigenetic memory, which needs continuous passaging to get into Limbo
- Right place and right time: small molecules reprogram cell fate of worm germ cells
- Caspase cleavage-mediated substrate change: switching function of Dicer between RNAi pathway and apoptosis pathway
- Some thoughts on focal adhesion disassembly: focal adhesion fades as retrograde flow