Dorothy Croall, Ph.D.
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Location: Hitchner Hall
Mailing Address: 5735 Hitchner Hall, Orono, ME 04469-5706
Biochemists study living things at the molecular level and try to answer questions about what specific molecules do and how, in cooperation with other molecules, they mediate dynamic changes in response to various cues. We think that PROTEINS are the most amazing group of diverse molecules and include catalytically active ENZYMES. For more than 30 years my research focus has been on proteins and proteostasis in eukaryotes. More specifically, we study the ubiquitous calcium regulated enzymes that cleave other proteins, the proteinases named CALPAINS and a protein that specifically inhibits them – CALPASTATIN. We are still trying to answer some important questions about their properties and functions. We exploit recombinant DNA technology to create variants of the proteins of interest; use E. coli to synthesize those proteins for us; use chromatography to purify the proteins and whatever analytical methods are required to try to answer questions of interest.
- There are at least 15 genes encoding relatives of the first calpains that were identified (calpains1 and 2), but only a few of the proteins have been studied in detail.
- The ‘family’ is evolutionary conserved from nematodes, fruit flies, to humans. This suggests they have important functions.
- They also must do something important during development because deletion of genes encoding either the catalytic subunit of calpain2 (CAPN2) or the small subunit (CAPNS1) it shares with other calpain isoforms is lethal.
- Mutation of selected calpains is linked to disease. E.g. Limb-Girdle muscular dystrophy (type IIA) is caused by malfunction of calpain3; calpain9 may be a tumor suppressor, calpain 14 esophagitis and mutations in calpain5 result in a rare type of blindness.
- Calcium ions are essential signal molecules that regulate many critical cellular processes such as of membrane repair, cell growth, movement, division, development, and death. Control of calpain conformation and function by calcium links them to
Current Projects share a methodological strategy to exploit the power of affinity capture (AC), in vitro, coupled with Mass Spectrometry (MS) and proteomics in order to discover substrates and other interacting proteins for both the well studied calpain-2 and a nonclassical calpain that is not well characterized, calpain5. For the MS analysis we collaborate with Dr. Calvin Vary, Director of the Protein, Nucleic Acid Analysis and Cell Imaging Core at Maine Medical Center Research Institute (MMCRI) The calpain5 project is an NIH funded through NINDS as a collaboration with Dr. James Geddes, Principal Investigator, at the University of Kentucky, Lexington KY.
- Calpain2 substrates and interacting partners in endothelial cells. Substantial evidence indicates that the proteolytic activity of calpains plays important roles in formation and maintenance of the vasculature. Identifying the key protein targets of calpain will provide critical mechanistic links needed to define the enzyme’s role in physiological or pathological events. We have established proof of concept that our AC-MS is successful and have identified some interesting calpain-2 partners. This project is currently not funded.
- Getting to know calpain5 (CAPN5) and its interacting partners: We began to explore the basic biochemistry of calpain 5 (CAPN5) and its role in the central nervous system as a collaboration with Dr. Geddes and colleagues in 2013. We hypothesize that this under-studied member of the calpain family participates in Ca2+signalling and proteostasis with important relevance to neuronal function. The project at UMaine aims to identify and confirm protein-protein interactions for CAPN5.
- Dutt, P. Croall, D.E., Arthur, J.S.C., DeVeyra, T., Williams, K, Elce, J.S. and Greer, P.A. m-Calpain is required for preimplantation embryonic development in mice. BioMed Central Developmental Biology 6, 3
- Croall, D.E. and Ersfeld, K (2007) The Calpains: Modular design and functional diversity . Genome Biology 8; 218.1-218.11.
- Croall, D.E., Vanhooser, L.M. and Cashon, RE Detecting the Active Conformation of Calpain-2 with Calpastatin-Based Reagents. In Press BBA: Proteins and Proteomics
- Croall, D.E. and Hatch, H. (2004) The regulation of calpain activity by calcium: a role for an IQ-motif. Ms in preparation.
- Croall, D.E. , Moffett, K. and Hatch, H. (2002) Casein zymography of calpains using a 4- (2-hydroxtethyl)-1-piperazineethnesulfonic acid- Imidiazole buffer. Analytical Biochemistry 304, 129-132
- Croall, D.E. (2000) Affinity chromatography methods for purifying calpains. in Methods in Molecular Biology 144, 33-40.
- Hosfield, C.M., Ye, Q., Arthur, J.S.C., Hegadorn, C., Croall, D.E., Elce, J.S., Jia, Z. (1999) Crystallization and X-ray crystallographic analysis of m-calpain, a calcium-dependent protease. Acta Cryst. D55, 1484-1486
- Dutt, P., Arthur, J.S.C., Croall, D.E. and Elce, J.S. (1998) m-calpain subunits remain associated in the presence of calcium. FEBS Lett. 436, 367-371.
- Potter, D.A., Tirnauer, J.S., Jansenn, R., Croall, D.E., Hughes, C.N., Mier, J., Maki, M. and Herman, I.M. (1998) Calpain regulates cell spreading and function of the cortical actin cytoskeleton. J. Cell Biol. 141, 647-662.
- Arora, A.S., deGroen, P., Croall, D.E., Emori, Y., and Gores, G. (1996) Hepatocellular carcinoma cells resist necrosis during anoxia by preventing phospholipase mediated calpain activation. J. Cellular Physiology. 167: 434-442.
- Croall, D.E., Chacko, S. and Wang, X. (1996) Cleavage of caldesmon and calponin by calpain: Substrate recognition is not dependent on calmodulin binding domains. Biochim. Biophys. Acta 1298: 276-284. . Biochim. Biophys. Acta 882:287-296.
- Spencer, M.J., Croall, D.E. and Tidball, J.G. (1995) Calpains are activated in necrotic fibers from mdx dystrophic mice. J. Biol. Chem. 270: 10909 – 10914.
- Croall, D.E. and McGrody, K.S. (1994) The domain structure of milli-calpain: Mapping the binding site for calpastatin. Biochemistry 33: 13223-13230.