George S. Bloom

Professor of Biology

Contact Information

 Postal Email Phone Web
 Gilmer Hall, 229
 Department of Biology
 PO Box 400328
 University of Virginia
 Charlottesville, VA
  22904-4328		 gsb4g@virginia.edu  Office:
 (434)243-3543
 Lab:
 (434)243-3544		 Click
Here

 

Research Interests

Cellular Morphogenesis and Moltility; Cell Biology of Alzheimer's Disease

Research in our laboratory is now focused primarily on two areas: the functions and regulation of proteins known as IQGAPs, and the cell biological basis of Alzheimer's disease (AD). We are also devoting a modest effort to study intracellular trafficking of caveolin-1.

IQGAPs are large scaffolding proteins that are intimately involved in controlling cell motility, morphogenesis and adhesion. Most of our work so far with these proteins has been directed at IQGAP1, and its role in coupling growth factor stimulation of cells to assembly in the cell cortex of branched actin filament networks. These networks function as the engines for plasma membrane protrusion during cell migration, and our results have indicated that IQGAP1 is required for their formation in many cell types.

The histopathological hallmark of Alzheimer's disease is the presence in brain of extracellular deposits containing ß-amyloid peptide fibrils plus intraneuronal neurofibrillary tangles, which are filaments composed of the protein, tau. The goal of our work on AD is to decipher the metabolic link that connects ß-amyloid and tau to damage neurons. We have found that tau expression makes microtubules hypersensitive to pre-fibrillar forms of ß-amyloid, and suspect that tau-dependent, ß-amyloid-induced microtubule disassembly is a seminal event in AD pathogenesis at the cellular level.

Caveolin-1 is the signature protein of cell surface caveolae, but we have found that vesicles and tubules containing the protein move constitutively along microtubules between the plasma membrane and various intacellular locations. During their excursions through the cytoplasm, these membrane transport intermediates frequently merge with membranes of the clathrin-dependent endocytotic system, and their transport is tightly controled by the actin-based motor protein, myosin Vc.

Selected Publications

  • Bloom GS, and Goldstein LSB. 1998. Cruising Along Microtubule Highways: How Membranes Move Through the Secretory Pathway. JOURNAL OF CELL BIOLOGY 140: 1277-1280. (Read pdf)


  • Fullerton AT, Bau M-Y, Conrad PA, and Bloom GS. 1998. In Vitro Reconstitution of Microtubule Plus End-directed, GTPγS-Sensitive Motility of Golgi Membranes. MOLECULAR BIOLOGY OF THE CELL: 2699-2714. (Read pdf)
    View Fragments Movie            
    View Tubules Movie               
    View GTPγS Movie

  • Mateer SC, McDaniel AE, Nicolas V, Habermacher GM, Lin M-JS, Cromer DA, King ME, and Bloom GS. 2002. The Mechanism for Regulation of the F-actin Binding Activity of IQGAP1 by Calcium/Calmodulin. JOURNAL OF BIOLOGICAL CHEMISTRY 277: 12,324-12,333. (Read pdf)
    View Calcium Response Movie
    View Calcium Reversal Movie            


  • Mundy DI, Machleidt T, Ying Y-S, Anderson RGW, and Bloom GS. 2002. Control of Caveolar Membrane Traffic by Microtubules and the Actin Cytoskeleton. JOURNAL OF CELL SCIENCE 115: 4327-4339. (Read pdf)
    View Movies

  • Yamaoka-Tojo M, Ushio-Fukai M, Hilenski L, Dikalov SI, Chen YE, Tojo T, Fukai T, Fujimoto M, Patrushev NA, Wang N, Bloom GS, and Alexander RW. 2004. IQGAP1, a Novel VEGF Receptor Binding Protein Involved in Redox-dependent Endothelial Migration and Proliferation. CIRCULATION RESEARCH 95: 276-283. (Read pdf)

  • Bloom GS, Ren K, and Glabe CG. 2005. Cultured Cell and Transgenic Mouse Models for Tau Patholgy Linked to ß-Amyloid BIOCHIMICA ET BIOPHYSICA ACTA MOLECULAR BASIS OF DISEASE 1739: 116-124. (Read pdf)

  • Morris, LE, Bloom GS, Frierson HF Jr., and Powell SM. 2005. Nucleotide Variants Within the IQGAP1 Gene in Diffuse-Type Gastric Cancers. Genes, Chromosomes and Cancer 42: 280-286. (Read pdf)