David G. Bear

Position:	Professor and Chair
Email:	dbear@salud.unm.edu
Phone:	505.277.8610
Fax:	505.277.2609
Office:	Clark #103

Education

• B.S. Chemistry, University of Arizona, 1972
• Ph.D. Chemistry, University of California at Santa Cruz, 1978
• NIH Postdoctoral Fellow, Institute of Molecular Biology, University of Oregon, 1978-1982

Research

Dr. Bear’s research program focuses on the structure and function of proteins that bind to messenger RNA (mRNA) and regulate mRNA processing and trafficking in mammalian muscle cells and in muscle cell diseases such as muscular dystrophies and the muscle cell cancer called rhabdomyosarcoma. The program currently has two major foci. The first project focuses on the role of the nuclear poly(A) binding protein PABPN1 in oculopharyngeal muscular dystrophy (OPMD). OPMD is an inherited adult-onset myopathy that is caused by a mutation in the PABPN1 gene. Interestingly, OPMD is extremely prevalent in the New Mexico Hispanic population. The Bear laboratory is currently using molecular biology, protein biochemistry, and single molecule electron microscopy imaging techniques to investigate the assembly of normal and OPMD mutant PABPN1 assembly on the mRNA poly(A) tail. The group is also interested in how PABPN1 levels are regulated in the cell and how the OPMD gene mutation is related to dysregulation of PAPBN1 gene expression. The second project focuses on the intracellular trafficking of the mRNA encoding the giant muscle protein titin. Titin is the largest known protein with a molecular weight of more than 3 million Daltons, and the titin mRNA is the largest known mature mRNA with more than 300 exons. Dr. Bear’s group is using electron microscopy and protein chemistry to examine the structure, processing and trafficking of the titin mRNA ribonucleoprotein complex in normal muscle cells and in rhabdomyosarcoma tumor cells.

Representative Publications

1. Keller, R., Kuehn, U., Aragon, M., Bornikova, L., Wahle, E. and Bear, D.G. (2000) The Nuclear Poly(A) Binding Protein, PABP2, Forms an Oligomeric Particle Covering the Length of the Poly(A) Tail. J. Mol. Biol. 297: 569-583.
2. Becher, M.W., Kotzak, J.A., Davis, L.E. and Bear, D.G. (2000) Intranuclear Inclusions in Oculopharyngeal Muscular Dystrophy Contain Poly(A) Binding Protein 2. Annals of Neurology 48: 812-815.
3. Becher, M.W., Morrison, L., Davis, L.E., Maki, W.C., King, M.K., Bicknell, J.M., Reinert, B.L., Bartolo, C., and Bear, D.G. (2001) Oculopharyngeal Muscular Dystrophy in Hispanic New Mexicans. J. Amer. Med. Assoc. 286: 2437-2440.
4. Bear, D.G., Fomproix, N., Soop, T., Kylberg, K. Bjorkroth, B., Masich, S. and Daneholt, B. (2003) Nuclear Poly(A) Binding Protein PABPN1 is Associated With RNA Polymerase II during Transcription and Accompanies the Released Transcript to the Nuclear Pore. Experimental Cell Res. 286: 332-344.
5. Chen, F.F., Liu, G.L., Gerion, D., Yin, Y., Kunchkarra, S., Mukherjee, B., Sarkar, A.H., Tsutakawa, S., Cooper, P.K., Bear, D.G., Jett, S.J., Alivisatos, A.P., Gray, J.W., and Lee, L.P. (2006). Nanoplasmonic Molecular Ruler for Nuclease Activity and DNA Footprinting (2006) Nature Nanotechnology 1: 47-52.