3syv

Publication Abstract from PubMed

BAR (Bin/amphiphysin/Rvs) domain-containing proteins participate in cellular membrane remodeling. The F-BAR proteins normally generate low-curvature tubules. However, in the PACSIN subfamily, the F-BAR domain from PACSIN 1 and 2 can induce both high- and low-curvature tubules. We found that unlike PACSIN 1 and 2, the PACSIN 3 could only induce low-curvature tubules. To elucidate the key factors that dictate the tubule curvature, crystal structures of all three PACSINs F-BAR domains were determined. A novel type of lateral interaction mediated by a wedge loop is observed between the F-BAR neighboring dimers. Comparisons of the structures of PACSIN 3 with PACSIN 1 and 2 indicate that the wedge loop of PACSIN 3 is more rigid, which influences the lateral interactions between assembled dimers. We further identified the residues that affect the rigidity of the loop by mutagenesis and determined the structures of two PACSIN 3 wedge loop mutants. Our results suggest that the rigidity-mediated conformations of the wedge loop correlate well with the various crystal packing modes and membrane tubulations. Thus, the rigidity of the wedge loop is a key factor in dictating tubule diameters.

The rigidity of the wedge loop in PACSIN 3 is a key factor in dictating the diameters of tubules.,Bai X, Meng G, Luo M, Zheng X J Biol Chem. 2012 May 9. PMID:22573331^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.