Diane Bassham

I am interested in the role of the vacuole in plant responses to nutrient limitation. Plant cells typically contain a large central vacuole that is responsible for a variety of processes including protein degradation, storage of metabolites and proteins, maintenance of turgor pressure and cell homeostasis. Upon exposure to certain stress conditions, non-essential cell components are broken down in the vacuole in order to recycle their constituents and maintain essential functions. This occurs by autophagy, a process by which portions of the cytoplasm are surrounded by membrane and delivered to the vacuole for degradation. I plan to use a variety of approaches to study the regulation and mechanism of autophagy in Arabidopsis. I would like to understand how plant cells perceive nutrient stress, how the signal is transduced within the cell and the ways in which the endomembrane system of the cell changes upon induction of vacuolar autophagy.

A second project in my lab is to determine how proteins are transported to the plant vacuole through the secretory pathway. Most vacuolar proteins are synthesized at the endoplasmic reticulum and are transported through the endomembrane system in small transport vesicles. We have identified several proteins that may be involved in vesicle transport to the vacuole, and are now characterizing their functions using biochemical and genetic approaches.

Selected Publications

Bassham DC, AA Sanderfoot, V Kovaleva, H Zheng and NV Raikhel. 2000. AtVPS45p complex formation at the trans-Golgi network. Mol Biol Cell 11: 2251-2265.

Bassham DC and NV Raikhel. 2000. Plant cells are not just green yeast. Plant Physiol 122: 999-1002.

Bassham DC and NV Raikhel. 2000. Unique features of the plant vacuolar sorting machinery. Curr Opin Cell Biol 12: 491-495.

Bassham DC and NV Raikhel. 1999. The prevacuolar t-SNARE AtPEP12p forms a 20S complex that dissociates in the presence of ATP. Plant J 19: 599-604.

Zheng H, DC Bassham, AS Conceição and NV Raikhel. 1999. The syntaxin family of proteins in Arabidopsis: a new syntaxin homologue shows polymorphism between two ecotypes. J Exp Bot 50: 915-924.

Bassham DC and NV Raikhel. 1998. An Arabidopsis VPS45p homologue implicated in protein transport to the vacuole. Plant Physiol 117: 407-415.

Conceição AS, D Marty-Mazars, DC Bassham, AA Sanderfoot, F Marty and NV Raikhel. 1997. The syntaxin homologue AtPEP12p resides on a late post-Golgi compartment in plants. Plant Cell 9: 571-582.

Bassham DC and NV Raikhel. 1996. Transport proteins in the plasma membrane and secretory system. Trends in Plant Sci 1: 15-20.

Matsuoka K, DC Bassham, NV Raikhel and K Nakamura. 1995. Different sensitivity to wortmannin of two vacuolar sorting signals indicates the presence of distinct sorting machineries in tobacco cells. J Cell Biol 130: 1307-1318.

Bassham DC, S Gal, AS Conceição and NV Raikhel. 1995. An Arabidopsis syntaxin homologue isolated by functional complementation of a yeast pep12 mutant. Proc Natl Acad Sci USA 92: 7262-7266.