Associate Professor, Animal Sciences
PhD Syracuse University
MS Biochemistry - StateUniversity of New York at Fredonia
BS Biology - State University of New York at Fredonia
Postdoctoral Fellow and Research Instructor for the Baylor College of Medicine Department of Cell Biology
All cells contain a set of proteins known as heat stress proteins (Hsps) that provide protection from various environmental stresses such as elevated temperatures, exposure to heavy metals and hypoxia. The levels of these proteins increase when cells are exposed to stresses and the increased levels help the cells survive. These proteins are named according to their molecular weight. The most studied of these proteins have molecular weights of approximately 70kDa and are therefore called the Hsp70-related family of stress proteins. Hsp70 helps the cell survive stresses by binding to partially denatured proteins and assisting to refold these proteins into more stable native structures.
The importance of Hsp70 as a cellular regulator has dramatically increased over the years due to its association with a number of other cellular processes including protein refolding, apoptosis, cell proliferation and protein degradation. Misfolded proteins are a characteristic of some neuromuscular diseases and therefore studies are focused on understanding the regulation of Hsp70 activity on protein refolding. In addition, elevated Hsp70 levels have been reported in a number of different types of cancer and lowering these levels causes cancer cells to undergo apoptosis. Therefore, understanding the regulation of Hsp70 will provide information on the regulation of a diverse number of cellular activities and will have importance in both basic as well as applied medical research. The long term goal of this laboratory is to understand how other proteins can regulate Hsp70.
This laboratory has discovered a novel Hsp70 inhibitory protein called HspBP1. In vitro studies have revealed that HspBP1 binds to and inhibits Hsp70 by removal of bound nucleotide. Further studies have shown that HspBP1 is the most abundant Hsp70 cochaperone in tissues and cells and is elevated in a number of tumors. Our laboratory has collaborated with a crystallography group to produce a model of HspBP1 binding to the ATPase domain of Hsp70.
In addition, we have found that HspBP1 is present in human sera and therefore an extracellular role for this protein has been suggested. We have reported that levels of HspBP1 are elevated in both the tumors and sera from breast cancer patients. Recently we have shown that HspBP1 can bind to the outside of cells and that extracellular HspBP1 stimulates phosphorylation of the EGF receptor. These new findings have provided support for the hypothesis that HspBP1 can function both inside and outside the cell. Current research is focused on the function of extracellular HspBP1 in cancer cell growth.
Yokoyama Y, Kuramitsu Y, Takashima M, Fujimoto M, Iizuka N, Terai S, Okita K, Sakaida I, Oka M, Raynes DA, Guerriero V, Nakamura K. 2008. Increased expression of heat shock protein-binding protein 1 and heat shock protein 70 in human hepatocellular carcinoma tissues. Mol Med Report. 2008 Mar-Apr;1(2):197-201.
Souza, A.P., Albuquerque , C., Torronteguy, C., Frasson, A., Maito, F., Pereira, L. s Duval da Silva, V., Felipe Zerwes, F., Raynes, D., Guerriero, V. and Cristina Bonorino. 2009. HspBP1 Levels are Elevated in Breast Tumor Tissue and Inversely Related to Tumor Aggressiveness. Cell Stress and Chaperones 14 (3): 301-10.
Evdonin A, Kinev A, Tsupkina N, Guerriero V, Raynes DA, Medvedeva N. 2009. Extracellular HspBP1 and Hsp72 synergistically activate epidermal growth factor receptor. Biol Cell. 101(6):351-60.
Graner, M.W., Raynes, D.A., Bigner, D.D, Guerriero, V. 2009. Heat shock protein 70-binding protein 1 is highly expressed in high-grade gliomas, interacts with multiple heat shock protein 70 family members, and specifically binds brain tumor cell surfaces. Cancer Science 100: 1871-1879.
Sedlackova L, Sosna A, Vavrincova P, Frýdl J, Guerriero V, Raynes D, Hromadnikova I. 2011. Heat shock protein gene expression profile may differentiate between rheumatoid arthritis, osteoarthritis, and healthy controls. Scand J Rheumatol. 2011 Mar 21. [Epub ahead of print]
Yashin DV, Dukhanina EA, Kabanova OD, Romanova EA, Lukyanova TI, Tonevitskii AG, Raynes DA, Gnuchev NV, Guerriero V, Georgiev GP, Sashchenko LP. 2011. The Heat Shock-binding Protein (HspBP1) Protects Cells against the Cytotoxic Action of the Tag7-Hsp70 Complex. J Biol Chem. 286(12):10258-64.