title: Localization of a centrin-like protein to higher plant plasmodesmata.
abstract: Antibodies against centrin, the ubiquitous calcium-binding contractile protein, recognized a 17 kDa protein in extracts of onion root tips and cauliflower florets. Using immunofluorescence microscopy, anti-centrin antibodies were localized to the developing cell plate of onion and cauliflower root tip cells. In cauliflower florets, these antibodies localized to the walls in a punctate manner, consistent with the distribution of plasmodesmata as shown by colocalization with callose. Anti-centrin antibodies were localized to plasmodesmata of onion root tips and cauliflower florets with immunogold electron microscopy. Furthermore, this label was concentrated around the necks of plasmodesmata. In contrast, an antibody against calmodulin, which is a closely related calcium-binding protein, did not label plasmodesmata. We propose that centrin is a component of calcium-sensitive contractile nanofilaments in the neck region of plasmodesmata and facilitates the calcium-induced regulation of intercellular transport.
authors.affiliation: School of Biological Sciences, University of Sydney, Australia. leila@bio.usyd.edu.au
authors.forename: L M
authors.initials: LM
authors.lastname: Blackman
authors.forename: J D
authors.initials: JD
authors.lastname: Harper
authors.forename: R L
authors.initials: RL
authors.lastname: Overall
mesh_terms: D001937:Brassica / Q000737:chemistry* / Q000648:ultrastructure; D002135:Calcium-Binding Proteins / Q000032:analysis*; D002473:Cell Wall / Q000737:chemistry; D002868:Chromosomal Proteins, Non-Histone; D008856:Microscopy, Fluorescence; D019697:Onions / Q000737:chemistry* / Q000648:ultrastructure; D010936:Plant Extracts; D010940:Plant Proteins / Q000032:analysis*; D018514:Plant Structures / Q000737:chemistry
chemical_list: D002135:Calcium-Binding Proteins; D002868:Chromosomal Proteins, Non-Histone; D010936:Plant Extracts; D010940:Plant Proteins; C056608:caltractin