Ying Gu
Assistant Professor of Biochemistry and Molecular Biology
262 North Frear LaboratoryUniversity Park, PA 16802
Websites
Research Interests
Mechanism of cellulose biosynthesis in arabidopsis
Research Summary
Cellulose is the most abundant biopolymer on earth. The great abundance of cellulose places it at the forefront as a primary source of biomass for renewable biofuels and a variety of efforts are underway to improve cellulose degradation. However, little is known about the mechanism by which plant cells make cellulose. Understanding the complex process of cellulose synthesis will be important for optimizing the use of cellulose as a renewable energy source. Cellulose microfibrils are synthesized at the plasma membrane by hexameric protein complexes, also known as cellulose synthase complexes (CSCs). The only known components of CSCs are cellulose synthase (CESA) proteins, first discovered in bacteria in 1990. The principal investigator recently identified a novel plant gene, CSI1, which associates with CESA complexes and are required for normal cellulose biosynthesis. CSI1, as the first non-CESA proteins associated with CSCs, opens up many opportunities. The successful identification of CSI1 prompts us to further explore molecular genetics and biochemical approaches in identification of additional players in CSCs. The cutting-edge live cell imaging will be used to visualize CSCs in living plant cells and to assess individual components’ function in CSCs. Together with biochemical, molecular genetics, and plant genetics approaches, we will pursue the following objectives aimed to unravel the mystery of cellulose biosynthesis in plants: 1) Identification and characterization of novel components in CSCs. 2) Investigate interactions between minimal components in CSCs. 3) Advance our understanding in assembly, delivery, and regulation of CSCs. Together, these studies will substantially increase our knowledge of how plant cells make cellulose and provide unprecedented perspective that aids to increase the efficiency of biomass-based energy production.
Figure 1 Imaging of CESA complexes (CSCs). (A) Hexameric CSCs, also known as rosettes, are observed by freeze fracture electron microscopy in algae, moss, and vascular plants. Images are adapted from Giddings et al. (Giddings et al., 1980). (B) CSCs are thought to be composed of 36 subunits of three types in vascular plants, with a diameter about 30 nm. (C) In vivo imaging of CSCs in Arabidopsis. CSI1 is the first non-CESA protein co-localized with CSCs. Bar = 5 μM.
Figure 2 Regulation of CSCs. CSCs are thought to be assembled in Golgi. After delivery of CSCs through vesicle trafficking route to plasma membrane, CSCs are activated by unknown mechanisms and begin to synthesize cellulose microfibrils. Cellulose deposition is guided by microtubules that lie beneath the plasma membrane. CSCs may be recycled through endocytic pathways or degraded upon interanalization.
Representative Publications
Representative Publications
- Li S, Lei L, Somerville C, Gu Y (2012) CSI1 represents a missing link between microtubules and cellulose synthase complexes. Proc. Natl. Acad. Sci. 109 (1): 185-190
- Bashline L, Du J, Gu Y (2011) The trafficking and behavior of cellulose synthase and a glimpse of potential cellulose synthesis regulators. Front. Biol. 6(5): 377-383
- Gu Y*, Somerville C (2010) Cellulose synthase interacting protein: a new factor in cellulose synthesis. Plant Signal. Behav. 5(12): 1571-1574 *Corresponding author
- Gu Y, Kaplinsky N, Bringmann M, Cobb A, Carroll A, Sampathkumar A, Baskin TI, Persson S, Somerville C (2010) Identification of a cellulose synthase-associated protein required for cellulose biosynthesis. Proc. Natl. Acad. Sci. 107:12866-12871
- Gu Y, Deng ZP, Paredez AR, Debolt S, Wang ZY, Somerville C (2008) Prefoldin6 is required for normal microtubule dynamics and organization in Arabidopsis. Proc. Natl. Acad. Sci. 105: 18064-18069
- Li S, Gu Y, Yan A, Lord E, Yang ZB (2008) RIP1 (ROP Interactive Partner 1)/ICR1 marks pollen germination sites and may act in the ROP1 pathway in the control of polarized pollen growth. Mol. Plant 6:1021-1035
- Jeon BW, Hwang JU, Hwang YK, Song WY, Fu Y, Gu Y, Bao F, Cho D, Kwak JM, Yang ZB, Lee Y (2008) The Arabidopsis small G protein ROP2 is activated by light in guard cells and inhibits light-induced stomatal opening. Plant Cell 20: 75-87
- Hwang JU, Gu Y, Lee YJ, Yang ZB (2006) A Oscillatory ROP GTPase activation leads the oscillatory polarized growth of pollen tubes. Mol. Biol. Cell 16: 5385-5399
- Gu Y, Li SD, Lord EM, Yang ZB (2006) Members of a novel class of Arabidopsis Rho guanine nucleotide exchange factors control Rho GTPase-dependent polar growth. Plant Cell 18: 366-381
- Fu Y*, Gu Y*, Zheng ZL, , Yang ZB (2005) Arabidopsis interdigitating cell growth requires two antagonistic pathways with opposing action on cell morphogenesis. Cell 120: 687-700 * Joint first authors
- Gu Y, Fu Y, Dowd P, Li SD, Vernoud V, Gilroy S, Yang ZB (2005) A Rho-family GTPase controls actin dynamics and tip growth via two counteracting downstream pathways in pollen tubes. J. Cell Biol. 169:127-138
- Gu Y, Wang ZH, Yang ZB (2004) ROP/RAC GTPase: an old new master regulator for plant signaling. Curr. Opin. Plant Biol. 7: 527-536
- Park J, Gu Y, Lee Y, Yang ZB, Lee Y (2004) Phosphatidic acid induces leaf cell death in Arabidopsis by activating the Rho-related small G protein GTPase-mediated pathway of reactive oxygen species generation. Plant Physiol. 134: 129-136
- Gu Y, Vernoud V, Fu Y, Yang ZB (2003) ROP GTPase regulation of pollen tube growth through the dynamics of tip-localized F-actin. J Exp. Bot. 54: 93-101
- Wu G*, Gu Y*, Li SD, Yang ZB (2001) A genome-wide analysis of Arabidopsis Rop-interactive CRIB motif-containing proteins that act as Rop GTPase targets. Plant Cell 13: 2841-2856 * Joint first authors
