Cis‐Golgi Cisternal Assembly and Biosynthetic Activation Occur Sequentially in Plants and Algae. (25th February 2013)

• Record Type: Journal Article
• Authors: Donohoe, Bryon S.; Kang, Byung‐Ho; Gerl, Mathias J.; Gergely, Zachary R.; McMichael, Colleen M.; Bednarek, Sebastian Y.; Staehelin, L. Andrew
• Is Part Of: Traffic. Volume 14:Number 5(2013:May)
• Page Start: 551
• Page End: 567
• Publication Date: 2013-02-25
• Subjects: Biological transport -- Periodicals; 571.6
• DOI: 10.1111/tra.12052
• Languages: English
• ISSNs: 1398-9219

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <bold>The cisternal progression/maturation model of Golgi trafficking predicts that <italic>cis</italic>‐Golgi cisternae are formed <italic>de novo</italic> on the <italic>cis</italic>‐side of the Golgi. Here we describe structural and functional intermediates of the <italic>cis</italic> cisterna assembly process in high‐pressure frozen algae (<italic>Scherffelia dubia</italic>, <italic>Chlamydomonas reinhardtii</italic>) and plants (<italic>Arabidopsis thaliana</italic>, <italic>Dionaea muscipula</italic>; Venus flytrap) as determined by electron microscopy, electron tomography and immuno‐electron microscopy techniques. Our findings are as follows: (i) The <italic>cis</italic>‐most (C1) Golgi cisternae are generated <italic>de novo</italic> from cisterna initiators produced by the fusion of 3–5 COPII vesicles in contact with a C2 <italic>cis</italic> cisterna. (ii) COPII vesicles fuel the growth of the initiators, which then merge into a coherent C1 cisterna. (iii) When a C1 cisterna nucleates its first cisterna initiator it becomes a C2 cisterna. (iv) C2‐Cn <italic>cis</italic> cisternae grow through COPII vesicle fusion. (v) ER‐resident proteins are recycled from <italic>cis</italic> cisternae to the ER via COPIa‐type vesicles. (vi) In <italic>S. dubia</italic> the C2 cisternae are capable of mediating the self‐assembly of scale protein complexes. (vii) In plants, ∼90% of native α‐mannosidase I localizes to medial Golgi cisternae. (viii) Biochemical activation of <italic>cis</italic> cisternae appears to coincide with their conversion to medial cisternae via recycling of medial cisterna enzymes. We propose how the different <italic>cis</italic> cisterna assembly intermediates of plants and algae may actually be related to those present in the ERGIC and in the pre‐<italic>cis</italic> Golgi cisterna layer in mammalian cells.</bold> </p> </abstract>