%D 2010 %0 MEDLINE %T The rice dynamin-related protein DRP2B mediates membrane trafficking , and thereby plays a critical role in secondary cell wall cellulose biosynthesis . %J Plant J %V 64 %P 56-70 %A Xiong G %A Li R %A Qian Q %A Song X %A Liu X %A Yu Y %A Zeng D %A Wan J %A Li J %A Zhou Y %M pub20663087 %X Membrane trafficking between the plasma membrane ( PM ) and intracellular compartments is an important process that regulates the deposition and metabolism of cell wall polysaccharides . Dynamin-related proteins ( DRPs ) , which function in membrane tubulation and vesiculation are closely associated with cell wall biogenesis . However , the molecular mechanisms by which DRPs participate in cell wall formation are poorly understood . Here , we report the functional characterization of Brittle Culm3 ( BC3 ) , a gene encoding OsDRP2B . Consistent with the expression of BC3 in mechanical it issues , the bc3 mutation reduces mechanical strength , which results from decreased cellulose content and altered secondary wall structure . OsDRP2B , one of three members of the DRP2 subfamily in rice ( Oryza sativa L ) , was identified as an authentic membrane-associated dynamin via in vitro biochemical analyses . Subcellular localization of fluorescence-tagged OsDRP2B and several compartment markers in protoplast cells showed that this protein not only lies at the PM and the clathrin-mediated vesicles , but also is targeted to the trans-Golgi network ( TGN ) . An FM4-64 uptake assay in transgenic plants that express green fluorescent protein-tagged OsDRP2B verified its involvement in an endocytic pathway . BC3 mutation and overexpression altered the abundance of cellulose synthase catalytic subunit 4 ( OsCESA4 ) in the PM and in the endomembrane systems . All of these findings lead us to conclude that OsDRP2B participates in the endocytic pathway , probably as well as in post-Golgi membrane trafficking . Mutation of OsDRP2B disturbs the membrane trafficking that is essential for normal cellulose biosynthesis of the secondary cell wall , thereby leading to inferior mechanical properties in rice plants .