title: BP-80 and homologs are concentrated on post-Golgi, probable lytic prevacuolar compartments.
abstract: Prevacuolar compartments (PVCs) are membrane-bound organelles that mediate protein traffic between Golgi and vacuoles in the plant secretory pathway. Here we identify and define organelles as the lytic prevacuolar compartments in pea and tobacco cells using confocal immunofluorescence. We use five different antibodies specific for a vacuolar sorting receptor (VSR) BP-80 and its homologs to detect the location of VSR proteins. In addition, we use well-established Golgi-markers to identify Golgi organelles. We further compare VSR-labeled organelles to Golgi organelles so that the relative proportion of VSR proteins in Golgi vs. PVCs can be quantitated. More than 90% of the BP-80-marked organelles are separate from Golgi organelles; thus, BP-80 and its homologs are predominantly concentrated on the lytic PVCs. Additionally, organelles marked by anti-AtPep12p (AtSYP21p) and anti-AtELP antibodies are also largely separate from Golgi apparatus, whereas VSR and AtPep12p (AtSYP21p) were largely colocalized. We have thus demonstrated in plant cells that VSR proteins are predominantly present in the lytic PVCs and have provided additional markers for defining plant PVCs using confocal immunofluorescence. Additionally, our approach will provide a rapid comparison between markers to quantitate protein distribution among various organelles.
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Yu-Bing
authors.initials: YB
authors.lastname: Li
authors.forename: Sally W
authors.initials: SW
authors.lastname: Rogers
authors.forename: Yu Chung
authors.initials: YC
authors.lastname: Tse
authors.forename: Sze Wan
authors.initials: SW
authors.lastname: Lo
authors.forename: Samuel S M
authors.initials: SS
authors.lastname: Sun
authors.forename: Guang-Yuh
authors.initials: GY
authors.lastname: Jauh
authors.forename: Liwen
authors.initials: L
authors.lastname: Jiang
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D015415:Biomarkers; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D018551:Solanum lycopersicum / Q000166:cytology / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D015388:Organelles / Q000378:metabolism*; D018532:Pisum sativum / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000378:metabolism; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015415:Biomarkers; D008164:Luminescent Proteins; D008565:Membrane Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins