Andrew StaehelinProfessor Emeritus
Porter room B412B
Ph.D., Swiss Federal Institute of Technology, 1966
Cell biology of the Golgi apparatus; electron microscopy of high pressure frozen cells; electron tomographic analysis of cells; public education about GM crops
We are interested in the spatial and functional organization of the membrane compartments and associated scaffolding systems of the secretory pathways of plant, algal, yeast and mammalian cells. The membranes of interest include the ER, Golgi apparatus, trans Golgi network (TGN), multivesicular bodies, vacuoles/ lysosomes, plasma membrane, and diverse transport vesicles. The main focus of our recent work has been on obtaining nano-scale, quantitative 3D information of secretory membrane systems in cells preserved by high pressure freezing and analyzed by electron tomography. Together with electron microscope immunolabeling experiments, these studies have provided increasingly tight morphological constraints for trafficking models based on light microscopic, biochemical and physiological investigations. Highlights of these research efforts include the 3D characterization of ER export sites, the demonstration that COPII vesicles are "born" with a 40 nm wide scaffolding layer that contains p115-type proteins. The identification of two types of COPI vesicles (COPIa for recycling proteins from cis-Golgi to ER; COPIb for recycling of TGN, trans and medial cisterna proteins). De novo cis-Golgi cisternae in plants, and algae arise from cisterna initiators produced by the fusion of 3 to 5 COPII vesicles, and the resulting cisternae remain biosynthetically inactive until they become medial-Golgi cisternae via COPIb-mediated enzyme recycling. In plants, transformation of trans-Golgi cisternae into Golgi-associated and then free TGN cisternae starts with cisternal peeling, a 30-35% reduction in cisternal membrane area, and an increase in secretory and clathrin-coated vesicles. These vesicles (~30) are released simultaneously via cisternal fragmentation, which also produces 1-4 residual cisterna fragments. Early endosomal markers co-localize with TGN markers in the TGN cisternae.
My GM crop educational activities originated with a course on plant biotechnology techniques in the 1990s, followed by service on a Boulder County Open Space GMO advisory committee. I now give lectures on this topic and occasionally write guest commentaries for the Boulder Daily Camera (see PowerPoint slides and articles below).
Takeuchi, M., I. Karahara, N. Kajimura, A. Takaoka, K. Murata, K. Misaki, S. Yonemura, L.A. Staehelin and Y. Mineyuki (2016)
Single microfilaments mediate the early steps of microtubule bundling during preprophase band formation in onion cotyledon epidermal cells.
Mol. Biol. Cell 27:1809-1820.
Staehelin, L.A. (2015) Membrane structure and membranous organelles. In: Biochemistry and Molecular Biology of Plants, 2nd ed., Chapter 1 (B.B.Buchanan, W. Gruissem and R. Jones, eds.). Wiley Publishing, pp. 2-44.
Staehelin, L.A. and B.-H. Kang (2008)
Nanoscale architecture of ER export sites and of Golgi membranes as determined by electron tomography. Plant Physiol. 147:1454-1468.
Kang, B.-H., E. Nielsen, M.L. Preuss, D. Mastronarde and L.A. Staehelin (2011)
Electron tomography of RabA4b and PI-4K1 labeled trans-Golgi network compartments in Arabidopsis. Traffic 12:313-329.
Donohoe, B.S., B.-H. Kang, M. Gerl, Z.R. Gergeley, C.M. McMichael, S. Bednarek and L.A. Staehelin (2012)
Cis-Golgi cisternal assembly and biosynthetic activation occur sequentially in plants and algae.
Day, K.J., L.A. Staehelin and B.S. Glick (2013)
A three-stage model of Golgi structure and function.
Histochem. Cell Biol. 140:239-249.
Gilkey, I.C. and L.A. Staehelin (1986)
Advances in Ultrarapid freezing for the preservation of cellular ultrastructure.
J. El.Micro. Tech. 3:177-210
Staehelin, L.A. (1986)
Chloroplast structure and supramolecular organization of photosynthetic membranes.
In: Encyclopedia of Plant Physiology (L.A. Staehelin and C.J. Arntzen, eds.), Springer-Verlag, Germany 19:1-84.
Staehelin, L.A. (1974)
Structure and function of intercellular junctions.
In: International Review of Cytology (G.H. Bourne and J.K. Danielli, eds.), Academic Press, NY 39:191-283.