Identification and characterization of COPIa- and COPIb-type vesicle classes associated with plant and algal Golgi. Export

@article{citeulike:2917689, abstract = {Coat protein I (COPI) vesicles arise from Golgi cisternae and mediate the recycling of proteins from the Golgi back to the endoplasmic reticulum (ER) and the transport of Golgi resident proteins between cisternae. In vitro studies have produced evidence for two distinct types of COPI vesicles, but the in vivo sites of operation of these vesicles remain to be established. We have used a combination of electron tomography and immunolabeling techniques to examine Golgi stacks and associated vesicles in the cells of the scale-producing alga Scherffelia dubia and Arabidopsis preserved by high-pressure freezing/freeze-substitution methods. Five structurally distinct types of vesicles were distinguished. In Arabidopsis, COPI and COPII vesicle coat proteins as well as vesicle cargo molecules (mannosidase I and sialyltransferase-yellow fluorescent protein) were identified by immunogold labeling. In both organisms, the COPI-type vesicles were further characterized by a combination of six structural criteria: coat architecture, coat thickness, membrane structure, cargo staining, cisternal origin, and spatial distribution. Using this multiparameter structural approach, we can distinguish two types of COPI vesicles, COPIa and COPIb. COPIa vesicles bud exclusively from cis cisternae and occupy the space between cis cisternae and ER export sites, whereas the COPIb vesicles bud exclusively from medial- and trans-Golgi cisternae and are confined to the space around these latter cisternae. We conclude that COPIa vesicle-mediated recycling to the ER occurs only from cis cisternae, that retrograde transport of Golgi resident proteins by COPIb vesicles is limited to medial and trans cisternae, and that diffusion of periGolgi vesicles is restricted.}, address = {Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.}, author = {Donohoe, B. S. and Kang, B. H. and Staehelin, L. A.}, citeulike-article-id = {2917689}, citeulike-linkout-0 = {http://dx.doi.org/10.1073/pnas.0609818104}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/17185411}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=17185411}, day = {2}, doi = {10.1073/pnas.0609818104}, issn = {0027-8424}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, keywords = {coatomer, copi, golgi, in\_vivo, isotypes, membrane, structure, tomography, traffic, vesicle}, month = {January}, number = {1}, pages = {163--168}, posted-at = {2008-06-23 12:06:36}, priority = {2}, title = {Identification and characterization of COPIa- and COPIb-type vesicle classes associated with plant and algal Golgi.}, url = {http://dx.doi.org/10.1073/pnas.0609818104}, volume = {104}, year = {2007} }

TY - JOUR ID - citeulike:2917689 L3 - citeulike-article-id:2917689 N2 - Coat protein I (COPI) vesicles arise from Golgi cisternae and mediate the recycling of proteins from the Golgi back to the endoplasmic reticulum (ER) and the transport of Golgi resident proteins between cisternae. In vitro studies have produced evidence for two distinct types of COPI vesicles, but the in vivo sites of operation of these vesicles remain to be established. We have used a combination of electron tomography and immunolabeling techniques to examine Golgi stacks and associated vesicles in the cells of the scale-producing alga Scherffelia dubia and Arabidopsis preserved by high-pressure freezing/freeze-substitution methods. Five structurally distinct types of vesicles were distinguished. In Arabidopsis, COPI and COPII vesicle coat proteins as well as vesicle cargo molecules (mannosidase I and sialyltransferase-yellow fluorescent protein) were identified by immunogold labeling. In both organisms, the COPI-type vesicles were further characterized by a combination of six structural criteria: coat architecture, coat thickness, membrane structure, cargo staining, cisternal origin, and spatial distribution. Using this multiparameter structural approach, we can distinguish two types of COPI vesicles, COPIa and COPIb. COPIa vesicles bud exclusively from cis cisternae and occupy the space between cis cisternae and ER export sites, whereas the COPIb vesicles bud exclusively from medial- and trans-Golgi cisternae and are confined to the space around these latter cisternae. We conclude that COPIa vesicle-mediated recycling to the ER occurs only from cis cisternae, that retrograde transport of Golgi resident proteins by COPIb vesicles is limited to medial and trans cisternae, and that diffusion of periGolgi vesicles is restricted. IS - 1 JF - Proceedings of the National Academy of Sciences of the United States of America SN - 0027-8424 AD - Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA. EP - 168 TI - Identification and characterization of COPIa- and COPIb-type vesicle classes associated with plant and algal Golgi. VL - 104 SP - 163 KW - coatomer KW - copi KW - golgi KW - in_vivo KW - isotypes KW - membrane KW - structure KW - tomography KW - traffic KW - vesicle AU - Donohoe, BS AU - Kang, BH AU - Staehelin, LA PY - 2007/01/02/ UR - http://dx.doi.org/10.1073/pnas.0609818104 ER -