Peter A. Greer, Ph.D.
Office Phone: 613-533-6000 x75081
Lab: 613-533-2813Fax: 613-533-6830
Botterell Hall, Rm. A308
- Professor of Pathology & Molecular Medicine and Biochemistry
- BSc, PhD, McGill University
Dr. Greer's Lab
Summary of Research Interests
The discovery of retroviral oncogenes in the 1970’s lead to the identification of their corresponding normal cellular proto-oncogene homologs. Their encoded proteins were subsequently found to play important signalling functions controlling cellular survival, growth, proliferation and differentiation. It seemed that mutations leading to over exuberant or altered activity of these oncoproteins could be at the root of cancer, and perhaps many other diseases. The pharmaceutical industry descended on these oncoproteins with drug discovery programs aimed at developing targeted small molecule inhibitor based therapeutics. We appeared on the verge of cures or clinical management of several major cancers and other diseases. However, with a few exceptions, essentially all targeted small molecule inhibitors have failed cancer clinical trials when used as single agents. Much like the organisms in which they develop, cancer cells are willey creatures capable of evolving to survive in face of seemingly insurmountable challenges. This often leads to cancer relapse after what often appears to be a successful clinical intervention. It is clear that we need to devise more ingenious multipronged attacks to prevent cancer relapse.
Our research explores several potential therapeutic targets, but it considers these in the context of the larger picture of mitogenic and survival signalling pathways available to the cancer cell. We reason that targeted inhibition of one pathway will select for cancer cells that have evolved to bypass that first pathway, perhaps by engaging alternative parallel or interacting pathways. It follows that we must anticipate this plasticity in the signalling apparatus of the surviving cancer cells and use an appropriate combination of targeted small molecule inhibitors which collectively prevent survival of all cancer cells.
Current projects in the lab explore the functions of Fps/Fes and Fer protein-tyrosine kinases and the calpain protease system in cellular signalling. We also investigate the effects of single or combinations of small molecule kinase inhibitors on the signalling apparatus of cancer cells. This work involves biochemistry, molecular biology, cell biology, transgenic and gene knock-out mice and animal physiology, and translational cancer research using clinical materials.
The Fps/Fes and Fer Protein Tyrosine Kinases
The Fps/Fes and Fer protein tyrosine kinases are encoded by the closely conserved fps/fes and fer proto-oncogenes. The fps/fes locus in humans and mouse is quite compact (approx. 13Kbp) and we have previously used DNA microinjection of mouse zygotes to generate transgenic mice strains which over-express either a wild type or mutant version of the Fps/Fes kinase (Greer et al., 1991; Greer et al., 1994). Interestingly, the activated fps/fes transgene caused vascular malformations in these mice, and this pointed to a potential role for Fps/Fes in angiogenesis. Because angiogenesis is a rate-limiting process during tumor growth and metastasis, regulation of Fps/Fes might provide an approach to treat cancer. This is currently being pursed by examining breast cancer progression in transgenic mouse lines which express either activated or inactivated Fps/Fes or Fer kinases. Fps/Fes and Fer have also been implicated in cytokine signaling, differentiation of hematopoietic stem cells, vesicular transport and several other cellular processes. Investigations into the biological functions of these tyrosine kinases represent the major focus of the lab.
The Calcium-regulated Protease, Calpain
Crystal structure of Calpain
The calcium-regulated protease calpain is ubiquitously expressed and is capable of cleaving a large number of cellular proteins. Although it has been intensively studied for several decades, and the crystal structure has recently been solved (Hosfield et al.1999) its biological functions are still poorly understood. We have recently used gene targeting in mice to knock out the Capn4 gene, which encodes an essential regulatory subunit of the two heterodimeric calpain isoforms, m and m. Embyros homozyogous for the Capn4 mutation die at midgestation with apparent defects in heart morphogenesis and erythropoiesis (Arthur et al., 2000). We have recently found that embryonic fibroblasts derived from these homozygous mutant embryos have defects in migration and this correlates with a failure to cleave cytoskeletal proteins which link the integrin receptors to the cytoskeleton at focal adhesions. We are currently using these calpain knockout mice and others in development to further explore the biological role of calpain.
Transgenic Mouse Models of Gene Function and Genetic Diseases
The laboratory mouse has been used for many decades as a genetic model for mammalian development and physiology. Its developmental, genetic and physiological characteristics are very similar to those of humans, so much of what we learn using the mouse is directly applicable to humans. In the last decade our ability to manipulate the mouse genome has advanced to the point where it is now possible to recreate mice stains with the specific genetic lesions that are associated with human diseases ranging from diabetes to learning disorders to cancers. Now that both the human and mouse genomes are nearly completely sequenced, the comparison shows that mouse and humans are genetically very closely related, and most of the approximately 40,000 human genes have mouse homologues which perform the same or similar biological functions. The next phase of the so called "post-genomic era" of biomedical research will involve an increasing use of mouse transgenic technology to determine the functions of all these genes, and to better understand how mutations in them, or different alleles of them may impact human health. Our laboratory uses transgenic mouse technology to explore the functions of a variety of genes. Our focus has been primarily on the proto-oncogenes encoding the Fps/Fes and Fer cytoplasmic protein-tyrosine kinases; but we also pursue active interests in the Eph receptor tyrosine kinases and their cell-associated Ephrin ligands, as well as the cytoplasmic calcium-regulated calpain proteases. We use specifically engineered transgenic mouse models of these genes to better understand the biological functions of their gene products, and to determine whether mutations in these or other genes contribute to human diseases.
Generation of Transgenic Mice by Zygote DNA Microinjection
The classic approach to making a transgenic mouse involves the random insertion of an engineered transcription unit into the mouse genome. This so called "transgene" is composed of a promoter designed to direct the desired tissue-specific expression pattern and the coding sequences of the gene of interest. These sequences are put together by molecular cloning methods and then microinjected into one of the two pronuclei of a one-cell stage (zygote) mouse embryo.
The transgene integrates somewhere in one of the twenty mouse chromosomes. After a brief overnight culture to the two-cell stage, the injected embryo is transferred into the oviduct of a surrogate mother. The transgene is transmitted to all the cells of the developing embryo, and the resulting founder transgenic mouse will carry the transgene as a stably expressed, and genetically transmissible component of its genome. This is an approach that we have used to show that an activating mutation in the fps/fes proto-oncogene can cause hemangiomas and other vascular malformations (Greer et al., 1994. Mol. Cell. Biol. 14:6755).
Generation of Knockout or Knock-in Mice by Gene Targeting
A more recently developed approach to manipulating the mouse genome, called gene targeting, has made it possible to disrupt specific endogenous mouse genes ("knockout"), or even to engineer very subtle mutations in endogenous genes that might only change a single amino acid of the encoded gene product ("knockin"). This approach involves a technique called homologous recombination. In essence, the target mouse gene is isolated and the desired mutation is engineered into it using molecular cloning methods. This ‘facsimile' of the gene, or targeting construct, is then introduced into cultured mouse embryonic stem (ES) cells to promote homologous recombination with the target gene.
A selection scheme is used to clone ES cells that have undergone the intended homologous recombination event. An appropriated targeted ES cell clone is then used to "make a mouse". This involves the aggregation of a clump of these recombinant ES cells with an eight-cell stage supporting mouse embryo.
During an overnight culture period the ES cells are incorporated into the developing embryo as it proceeds through the early developmental stage called blastocyst formation (Insert time lapse of blastocyst formation). These embryos are then transferred into the uterus of a surrogate mother and the ‘chimeric' embryos develop to term. We can tell immediately if the ES cells have contributed to the mouse because the ES cells we use are from a pigmented mouse strain while the supporting embryos are from an albino strain. Newborn chimeric mice have clearly visible pigmented eyes and during the next few days they also begin to display pigmented skin and hair. With luck, the ES cells will also have contributed to the gonad; and when they are bred, their offspring will carry the targeted gene in all their cells (Insert picture of 129SvJ litter and chimeric father x CD1 mother).
This is the approach that is used to make gene knock out mice and see how deletion of a particular gene affects development or physiological processes in an adult mouse. We have used this approach to either delete genes (knockout) preventing expression of the gene product altogether (Arthur et al., 2000. Mol. Cell. Biol. 20:4474) or to introduce subtle mutations (knock-in) that effect the enzymatic activity of the encoded gene products (Senis et al., 1999. Mol. Cell. Biol. 19:7436; Craig et al., Mol. Cell. Biol. 21:603).
Once you've generated your transgenic mouse strain its time to figure out if the genetic alteration has caused any particular developmental or physiological defects which would provide clues about the function of the targeted gene. Our lab is particularly interested in genes that play roles in hematopoietic development, so much of our analysis has focussed on lineage analysis of cells in the peripheral blood, bone marrow, spleen and thymus. This involves flow cytometry using antibodies directed against lineage-specific cell surface antigens. We also culture progenitor cells from bone marrow in semi-solid matrix in the presence of different cytokines and growth factors to determine if the hematopoietic progenitor cells are still capable of normal proliferation and differentiation under defined in vitro conditions. As two of the genes we are focussed on encode protein-tyrosine kinases implicated in the Jak-Stat signalling pathway, we also perform detailed biochemical analysis in cells isolated from the mice to determine if the genetic alteration has effected those signalling pathways (Insert figure of GM-CSF signaling pathway).
A more recent addition to our arsenal of analytical tools is the DNA microarray. Using microarray technology we can rapidly profile the expression of tens of thousands of genes. We are using this approach to determine for example, whether gene expression in macrophages in response to stimulation with granulocyte-macrophage colony stimulating factor is effected by loss of fps/fes tyrosine kinase activity. Queen's University is a satellite of the Ontario DNA Microarray Consortium. DNA microarrays are obtained from the core facility located in Toronto, and our local facility provides microarray analysis as a service.
Angiogenesis and inflammation
We are also interested in how the fps/fes and fer tyrosine kinases may influence development and function of the vasculature. Using intra vital microscopy we have recently found that fer-deficient mice display and enhanced inflammatory response to endotoxin challenge (Insert time lapse of cremaster vessels). We are also using time lapse video analysis of cultured cells to explore the involvement of these and other gene products on cell-cell and cell-matrix interactions, including those involved in directed endothelial cell migration during tumour-associated angiogenesis (Insert time lapse of C166 migration). Angiogenesis and inflammation play important roles in a number of diseases including cancer, arthritis, allergy and inflammatory bowel disease. A better understanding of how these physiological processes are regulated at the genetic and molecular levels should ultimately lead to new approaches to control them in the context of these various diseases.
Fluorescence Energy Transfer Analysis of Protein-protein Interactions
Ultimately we need to know how gene products interact with one another at the subcellular and molecular level in order to fully understand their functions. The expression of chimeric proteins containing the green fluorescent protein (GFP) domain fused to the protein of interest has provided us with a valuable approach to directly visualize proteins in live cells using confocal fluorescence microscopy. We have used this approach to examine the subcellular localization of the fps/fes and fer kinases in relation to other proteins which are markers for specific subcellular organelles. We are now developing an adaptation of this approach called fluorescence energy transfer (FRET) to explore molecular interactions of proteins.
The Eph receptor tyrosine kinases and their cell-associated ephrin ligands
Eph receptor tyrosine kinases have been shown to play important roles in axon pathfinding during establishment of neuronal connections in the developing nervous system, and more recently in vasculogenesis and angiogenesis. We have previously used the zebrafish as a model system to explore the developmental expression patterns of Eph receptor tyrosine kinases. More recently we have begun investigating the involvement of these kinases and their cell-associated ligands, the Ephrins, in cell-cell interactions during angiogenesis. Our hope is that small- molecule inhibitors of Eph-Ephrin interactions might provide an approach to block tumor-associated angiogenesis. We are currently developing time lapse analysis of cultured vascular endothelial cells to explore this approach.
Shimada, M., Greer, P.A., McMahon, A., Bouxsein, M.L., and Schipani, E. 2008. In vivo targeted deletion of Capn4 in osteoblasts impairs osteoblast function and bone formation. J. Biol. Chem. 283:21002-21010. http://www.ncbi.nlm.nih.gov/pubmed/18515801?ordinalpos=2&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Shapovalova, Z., Tabunshchyk, K., Püschel, A.W., and Greer, P.A. 2007. The Fer protein tyrosine kinase mediates a neurite collapse response to Semaphorin 3A in dorsal root ganglion neurons. BMC Developmental Biology 7:133. http://www.ncbi.nlm.nih.gov/pubmed/18053124?ordinalpos=7&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Gao, Y., Scott, M., Truesdell, P., and Greer, P.A. 2007. Fer-mediated cortactin phosphorylation is associated with efficient fibroblast migration and is dependent on reactive oxygen species generation during integrin-mediated cell adhesion. Molecular and Cellular Biology 27:6140-6152. http://www.ncbi.nlm.nih.gov/pubmed/17606629?ordinalpos=10&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Parsons, S., Mewburn, J.D., Truesdell, P. and Greer, P.A. 2007. The Fps/Fes kinase regulates leukocyte recruitment and extravasation during inflammation. Immunology 122:542-550. http://www.ncbi.nlm.nih.gov/pubmed/17627769?ordinalpos=9&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Visram, H., and Greer, P.A., 2006. 17 beta-estradiol and Tamoxifen Stimulate Rapid and Transient ERK Activation in MCF-7 Cells via Distinct Signaling Mechanisms. Cancer Biology and Therapy 5: 1677-82. http://www.ncbi.nlm.nih.gov/pubmed/17106250?ordinalpos=16&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Parsons, S., and Greer, P.A., 2006. The Fps/Fes kinase regulates the inflammatory response to endotoxin through down regulation of TLR4, NF-B activation, and TNF- secretion in macrophages. J. Leukocyte Biology 80:1522-8. http://www.ncbi.nlm.nih.gov/pubmed/16959897?ordinalpos=18&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Tan, Y., Dourdin, N., Wu, C., De Veyra, T., Elce, J.S., and Greer, P.A. 2006. Conditional disruption of ubiquitous calpains in the mouse. Genesis 44: 297-303. http://www.ncbi.nlm.nih.gov/pubmed/16783822?ordinalpos=20&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Tan, Y., Wu, C., De Veyra, T., and Greer, P.A., 2006. Ubiquitous calpains promote both apoptosis and survival signals in response to different death stimuli. J. Bio. Chem. 281: 17689-98.http://www.ncbi.nlm.nih.gov/pubmed/16632474?ordinalpos=23&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Tan, Y., Dourdin, N., Wu, C., De Veyra, T., Elce, J.S. and Greer, P.A. 2006. Ubiquitous Calpains Promote Caspase-12 and Jnk Activation During ER Stress-Induced Apoptosis. J. Biol. Chem. 281:16016-24.http://www.ncbi.nlm.nih.gov/pubmed/16597616?ordinalpos=24&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Dutt, P., Croall, D.E., Arthur, J.S.C., De Veyra, T., Williams, K., Elce, J.S., and Greer, P.A. 2006. m-Calpain is required for preimplantation embryonic development in mice. BMC Dev. Biol. 6:3. http://www.ncbi.nlm.nih.gov/pubmed/16433929?ordinalpos=29&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Zirngibl, R.A., Gao, Y., Muller, W.J., Jia, Z., and Greer, P.A. 2005 An identity crisis for fps/fes: Oncogene or tumour-suppressor ? Cancer Research. 65:3518-3522. http://www.ncbi.nlm.nih.gov/pubmed/15867340?ordinalpos=39&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Demarchi, F., Bertoli, C., Greer, P.A., and Schneider, C. 2005. Ceramide triggers an NF-kB dependent survival pathway through calpain-mediated degradation of p105. Cell Death and Differentiation 12:512-522. http://www.ncbi.nlm.nih.gov/pubmed/15933726?ordinalpos=37&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Qi, W., Ebbert, K.V.J., Craig, A.W.B., Greer, P.A., McCafferty, D.-M. 2005. Absence of Fer protein-tyrosine kinase exacerbates endotoxin-induced intestinal epithelial barrier dysfunction in vivo. GUT 54:1091-1097. http://www.ncbi.nlm.nih.gov/pubmed/16009680?ordinalpos=35&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Shimada, M., Mahon, M.J., Greer, P.A. and Serge, G.V. 2005. The receptor for parathyroid hormone and parathyroid hormone-related peptide is hydrolyzed and its signaling properties are altered by directly binding the calpain small subunit. Endocrinology. 146:2336-44. http://www.ncbi.nlm.nih.gov/pubmed/15691895?ordinalpos=46&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Gao, Y., Bates, B., Zirngibl, R.A., and P.A. Greer. 2004. Activated Fps/Fes tyrosine kinase regulates erythroid differentiation and survival. Experimental Hematology 32:935-45. http://www.ncbi.nlm.nih.gov/pubmed/15504549?ordinalpos=49&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Senis, Y., Samis, J., Gao, Y., Richardson, M., Lee, D.H., and Greer, P.A. 2004 Hemostatic and hematological abnormalities in gain-of-function fps/fes transgenic mice are associated with the angiogenic phenotype. Journal of Thrombosis and Haemostasis 2:2009-2019. http://www.ncbi.nlm.nih.gov/pubmed/15550033?ordinalpos=47&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Huynh, H., Bottini, N. Williams, S., Cherepanov, V., Musumeci, L., Saito, K., Bruckner, S., Vachon, E., Wang, X., Kruger, J., Chow, C.-W., Pellecchia, M., Monosov, E., Greer, P.A., Trimble, W., Downey, G.P., and Mustelin, T. 2004. Control of vesicle fusion by a tyrosine phosphatase. Nature Cell Biology 6:831-839. http://www.ncbi.nlm.nih.gov/pubmed/15322554?ordinalpos=51&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Xu, G., Craig, A., Greer, P., Miller, M., Anastasiades, P., Lilien, J., and Balsamo, J. 2004 Continous association of cadherin with b-catenin requires the non-receptor tyrosine kinase Fer. Journal of Cell Science 117:3207-3219. http://www.ncbi.nlm.nih.gov/pubmed/15226396?ordinalpos=52&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Fan, L., Di Ciano-Oliveira, C., Weed, S.A., Craig, A.W.B., Greer, P.A., Rotstein, O.D., and Kapus, A., 2004. Actin depolymerization-induced tyrosine phosphorylation of cortactin: The role of Fer kinase. Biochemical Journal 380:581-91. http://www.ncbi.nlm.nih.gov/pubmed/15030313?ordinalpos=54&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Mewburn, J., Vincent, S.G., Fisher, J.T., and Greer, P.A. 2004. Vascular defects in gain-of-function fps/fes transgenic mice correlate with PDGF- and VEGF-induced activation of mutant Fps/Fes kinase in endothelial cells. Journal of Thrombosis and Haemostasis 2:820-32. http://www.ncbi.nlm.nih.gov/pubmed/15099290?ordinalpos=53&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sedarous, M., Keramaris, E., O’Hare, M., Melloni, E., Slack, R.S., Elce, J., Greer, P., and Park, D.S. 2003. Calpains mediate p53 activation and neuronal death evoked by DNA damage. J. Biol. Chem. 278: 26031-38. http://www.ncbi.nlm.nih.gov/pubmed/12721303?ordinalpos=69&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Sangrar, W., Gao, Y., Zirngibl, R.A., Scott, M.L., and P.A. Greer. 2003. The fps/fes proto-oncogene regulates hematopoietic lineage output. Experimental Hematology 31:1259-1267. http://www.ncbi.nlm.nih.gov/pubmed/14662333?ordinalpos=58&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Haigh, J. J., Ema, M., Haigh, K., Gertsenstein, M., Greer, P.A., Rossant, J., Nagy, A., and Wagner, E.F. 2004. Activated Fps/Fes partially rescues the in vivo developmental potential of Flk1 deficient vascular progenitor cells. Blood 103 (3): 912-920. http://www.ncbi.nlm.nih.gov/pubmed/14525765?ordinalpos=61&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Senis, Y.A., Craig, A.W.B., and Greer, P.A. 2003. Fps/Fes and Fer protein-tyrosine kinases play redundant roles in regulating hematopoiesis. Experimental Hematology 31: 673-681. http://www.ncbi.nlm.nih.gov/pubmed/12901971?ordinalpos=66&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Senis, Y.A., Sangrar, W., Zirngibl, R., Craig, A.W.B., Lee, D.H. and Greer, P.A. 2003. Fps/Fes and Fer nonreceptor protein-tyrosine kinases regulate collagen- and ADP- induced platelet aggregation J. Thrombosis and Haemostasis 1:1062-1070. http://www.ncbi.nlm.nih.gov/pubmed/12871378?ordinalpos=67&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Craig, A.W.B. and Greer, P.A. 2002. Fer kinase is required for sustained p38 kinase activation and maximal chemotaxis of activated mast cells Mol. Cell. Biol. 22:(18) 6363-6374. http://www.ncbi.nlm.nih.gov/pubmed/12192036?ordinalpos=75&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Greer, P.A. Closing in on the biological roles of Fps/Fes and Fer protein-tyrosine kinases. 2002. Nature Reviews Molecular Cell Biology 3:278-289. http://www.ncbi.nlm.nih.gov/pubmed/11994747?ordinalpos=80&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
McCafferty, D.M., Craig, A.W.B., and Greer, P.A. 2002. Absence of Fer protein-tyrosine kinase exacerbates leukocyte recruitment in response to endotoxin. J. Immunol. 168:4930-4935. http://www.ncbi.nlm.nih.gov/pubmed/11994443?ordinalpos=81&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Zirngibl, R., Senis, Y., and Greer, P.A. 2002. Enhanced endotoxin-sensitivity in Fps/Fes-null mice with minimal defects in hematopoietic homeostasis. Mol. Cell. Biol. 22:2472-2486. http://www.ncbi.nlm.nih.gov/pubmed/11909942?ordinalpos=82&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Craig, AW.B., Zirngibl, R., Williams, K., Cole, L.A. and Greer, P.A. 2001. Mice devoid of Fer protein-tyrosine kinase activity are viable and fertile, but display reduced cortactin phosphorylation. Molecular and Cellular Biolology 21:603-613. http://www.ncbi.nlm.nih.gov/pubmed/11134346?ordinalpos=95&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Arthur, J.S.C., Elce, J.S., Hegadorn, C., Williams, K. and Greer, P.A. 2000. Disruption of murine calpain small subunit gene, Capn4: Calpain is essential for embryonic development but not for cell growth and division. Molecular and Cellular Biololgy20:4474-4481. http://www.ncbi.nlm.nih.gov/pubmed/10825211?ordinalpos=105&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
Senis, Y., Zirngibl, R., McVeigh, J., Haman, A., Hoang, T., and Greer, P.A. 1999. Targeted disruption of the murine fps/fes proto-oncogene reveals that Fps/Fes kinase activity is dispensable for hematopoiesis. Molecular and Cellular Biology19:7436-7446. http://www.ncbi.nlm.nih.gov/pubmed/10523632?ordinalpos=111&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum
last updated: 8 Aug 2008