Overexpression of a plant reticulon remodels the lumen of the cortical endoplasmic reticulum but does not perturb protein transport.
We have cloned a member of the reticulon (RTN) family of Arabidopsis thaliana (RTNLB13). When fused to yellow fluorescent protein (YFP) and expressed in tobacco leaf epidermal cells, RTNLB13 is localized in the endoplasmic reticulum (ER). Coexpression of a soluble ER luminal marker reveals that YFP-tagged, myc-tagged or untagged RTNLB13 induces severe morphological changes to the lumen of the ER. We show, using fluorescence recovery after photobleaching (FRAP) analysis, that RTNLB13 overexpression greatly reduces diffusion of soluble proteins within the ER lumen, possibly by introducing constrictions into the membrane. In spite of this severe phenotype, Golgi shape, number and dynamics appear unperturbed and secretion of a reporter protein remains unaffected.
Tolley
Nicholas
N
Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
Sparkes
Imogen A
IA
Hunter
Paul R
PR
Craddock
Christian P
CP
Nuttall
James
J
Roberts
Lynne M
LM
Hawes
Chris
C
Pedrazzini
Emanuela
E
Frigerio
Lorenzo
L
D017360:Arabidopsis / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000096:biosynthesis*; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D036681:Fluorescence Recovery After Photobleaching; D006056:Golgi Apparatus / Q000378:metabolism / Q000648:ultrastructure; D018613:Microscopy, Confocal; D010802:Phylogeny; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism
D029681:Arabidopsis Proteins; D011994:Recombinant Proteins