Andrew M. Scharenberg, M.D.
Professor, Pediatrics and
Adjunct Professor, Immunology

Department of Pediatrics
University of Washington
Seattle Children's Research Institute
1900 9th Avenue
Box 359300-C9S-7
Seattle, WA 98101
Tel: 206.987.7314
Fax: 206.987.7310
Email: andrewms@u.washington.edu

The Scharenberg Lab Homepage

Dr. Scharenberg received his medical degree from the University of North Carolina School of Medicine in 1990 and completed his residency at UNC Children's Hospital in 1993. He underwent postdoctoral training in Immunology in Dr. Jean-Pierre Kinet's lab at the NIH and the Division of Experimental Pathology, Beth Israel Deaconess Medical Center, before joining the faculty of Harvard Medical School as an Assistant Professor in 1998. Dr. Scharenberg joined the faculty at the University of Washington in November 2000, and is also an attending physician at Seattle Children's Hospital.  At Seattle Children's, he participates in the Immunodeficiency Clinic and the inpatient Immunology consult service, and runs a 12-member laboratory focused on lymphocyte physiology and gene repair. He was chosen as the American Pediatric Society/Society for Pediatric Research National Young Investigator Award winner in 2002; and elected to the American Society for Clinical Investigation, one of the oldest and most esteemed organizations of physician-scientists, in 2008. He is co-director for the Northwest Genome Engineering Consortium, a group of Seattle area investigators who are working on a new approach to the treatment of inherited diseases; and a member to the Transplantation Biology Consortium Program at Fred Hutchinson Cancer Research Center.

Current laboratory research focus:

The Scharenberg laboratory is interested in signal transduction mechanisms and cation channel function in the immune system, and engineering of homing endonucleases for gene repair applications in inherited immune deficiencies. Current effort is centered in two areas:

1) Signal transduction in immune cells, particularly signaling pathways affected in primary immune deficiencies and those involving ion channels.

a. The role of ADP-ribose in regulation of calcium entry via TRPM2. We have recently demonstrated that the TRPM2 ion channel is expressed in immunologic cells and is gated specifically by ADP-ribose produced by mitochondria (Nature, 411: 590-595; 2001; J. Biol Chem 280(7):6138-48, 2005). As virtually nothing is known about the biochemistry of ADP-ribose, our understanding of the processes which utilize this pathway is also rudimentary. Our approach at present has been to focus on developing methods for the measurement of intracellular ADP-ribose, analyzing the relationship between oxidant stress and ADP-ribose, characterizing the phenotype of cells lacking a key enzyme for the breakdown of ADP-ribose, and analyzing the structure/function relationships of TRPM2.

b. Characterization of a novel divalent cation entry pathway mediated by TRPM7. We have cloned a novel ion channel, designated TRPM7, which regulates the entry of all types of divalent cations into many types of cells, including all immune cell types so far analyzed. It is unique in having an intrinsic protein kinase domain of presently unknown function. We have recently demonstrated that this protein is a central regulator of magnesium homeostasis in immune cells (Cell, 2003, 114(2):191-200), and are presently focusing on understanding its role in this process, and the link between magnesium homeostasis and control of cell proliferation.

2) Use of homing endonucleases in targeted gene repair of genes responsible for primary immune deficiencies. A new approach to gene therapy involves targeted repair of a gene via the induction of a double strand break at or near the mutation site. We are pursuing two projects related to developing methods required for executing gene repair, which are now supported by an NIH Roadmap grant:

a. Engineering of homing endonucleases to cleave at novel recognition sites. Homing endonucleases are rare cutting enzymes which are of potential use in inducing double strand breaks at desired sites, but techniques are needed to generate new homing endonucleases which cut at desired sites. This project aims to evaluate several approaches for modifying homing endonuclease cutting sites, and involves collaboration between our group, David Baker's protein design group, Barry Stoddard's structural biology group, and Ray Monnat's homing endonuclease biology group.

b. Construction of animal models for development of homing endonucleases for double strand break-induced gene repair of immune cells. Methods for use of homing endonucleases in gene repair are not presently optimized. This project will create an animal model for evaluation of methods for homing endonuclease and DNA repair template introduction into immune cells. This project is a collaboration with David Rawlings gene therapy group, Hans-Peter Kiem's stem cell transplantation and gene therapy group, and Nancy Maizels DNA repair group.

For more information about Dr. Scharenberg’s research programs:

http://research.seattlechildrens.org/about/feat_research/repairing_genes.asp
http://research.seattlechildrens.org/centers/immunity_vaccines/ngec/
http://research.seattlechildrens.org/centers/immunity_and_immunotherapies/gene_therapy_and_repair.asp

Graduate students training in the Scharenberg lab: Jordan Jarjour (Immunology); Sarah Baxter and Marcia Paddock (MSTP); Michael Certo abd Kyle Jacoby (MCB)

Selected publications:

Rawlings D.J.*, Scharenberg A.M.*, Park H., Wahl M.I., Lin S., Kato R.M., Fluckiger A.C., Witte O.N. and Kinet J.P. Activation of BTK by a phosphorylation mechanism initiated by SRC family kinases. Science, 271, 822-825, 1996.

Scharenberg A.M., and Kinet J-P. The emerging field of receptor-mediated inhibitory signaling: SHP or SHIP, Cell, 87, 961-964, 1996.

Gupta N., Scharenberg A.M., Burshtyn D.N., Lioubin M., Rohrschneider L.R., Kinet J-P., and Long E.O. Killer cell inhibitory receptors and FcgRIIb1 utilize distinct negative signaling pathways, J. Exp. Med., 186:473-478, 1997.

El-Hillal O., Kurosaki T., Yamamura H., Kinet J-P. and Scharenberg A.M. Syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction, Proc. Natl. Acad. Sci. (USA), 94:1919-1924,1997.

Scharenberg A.M., El-Hillal O., Fruman D.A., Li Z., Beitz L.O. , Lin S., Gout I., Waterfield M.D., Witte O.N., Cantley L.C., Rawlings D.J., and Kinet J-P. Phosphatidylinositol-3,4,5-trisphosphate controls calcium signaling by initiating Tec-kinase dependent activation of PLCg, Embo 17: 1961-1972, 1998.

Fluckiger A.C., Lei Z. Kato R.M., Wahl M.I., Ochs H., Kinet J-P., Witte O.N., Longnecker R.,Scharenberg A.M., and Rawlings D.J. Regulation of sustained calcium influx by Tec family tyrosine kinases, Embo J., 17:1973-1985, 1998.

Scharenberg A.M., and Kinet J-P. PtdIns-3,4,5-P3: A regulatory nexus between tyrosine kinases and sustained calcium signals, Cell, 94(1):5-8,1998.

Perraud A.L., Fleig A., Dunn C.A., Bagley L.A., Launay P., Schmitz C., Stokes A.J., Zhu Q., Bessman M.J., Penner R., Kinet J.P. and Scharenberg A.M. ADP-ribose gating of the calcium-permeable LTRPC2 channel revealed by Nudix motif homology. Nature, 411, 595-599, 2001.

Nadler M.J., Hermosura M.C., Inabe K., Perraud A.L., Zhu Q., Stokes A.J., Kurosaki T., Kinet J.P., Penner R., Scharenberg A.M. and Fleig A. LTRPC7 is a Mg.ATP-regulated divalent cation channel required for cell viability. Nature, 411, 590-595, 2001.

Launay P., Fleig A., Perraud A.L., Scharenberg A.M., Penner R. and Kinet J.P. TRPM4 is a Ca2+-activated nonselective cation channel mediating cell membrane depolarization. Cell, 109, 397-407, 2002.

Schmitz C., Perraud A.L., Johnson C.O., Inabe K., Smith M.K., Penner R., Kurosaki T., Fleig A. and Scharenberg A.M.  Regulation of vertebrate cellular Mg2+ homeostasis by TRPM7. Cell, 114, 191-200, 2003.

Shen B.W., Perraud A.L., Scharenberg A.M. and Stoddard B.L. The crystal structure and mutational analysis of human NUDT9. J Mol Biol, 332, 385-398, 2003.

Saito K., Tolias K.F., Saci A., Koon H.B., Humphries L.A., Scharenberg A. M., Rawlings D.J., Kinet J.P. and Carpenter C.L. BTK regulates PtdIns-4,5-P2 synthesis: importance for calcium signaling and PI3K activity. Immunity, 19, 669-678, 2003.

Takezawa R., Schmitz C., Demeuse P., Scharenberg A.M., Penner R. and Fleig A. Receptor-mediated regulation of the TRPM7 channel through its endogenous protein kinase domain. Proc Natl Acad Sci U S A, 101, 6009-6014, 2004.

Perraud A.L., Takanishi C.L., Shen B., Kang S., Smith M.K., Schmitz C., Knowles H.M., Ferraris D., Li W., Zhang J., Stoddard B.L. and Scharenberg A.M. Accumulation of free ADP-ribose from mitochondria mediates oxidative stress-induced gating of TRPM2 cation channels. J. Biol. Chem. 280, 6318-6148, 2005.

Matthews S.A., Liu P., Spitaler M., Olson E.N., McKinsey T.A., Cantrell D.A. and Scharenberg A.M. Essential Role for Protein Kinase D Family Kinases in the Regulation of Class II Histone Deacetylases in B Lymphocytes. Mol. Cell. Biol.  26, 1569-1577, 2006.

Song Y., Dayalu R., Matthews S.A. and Scharenberg A.M. TRPML cation channels regulate the specialized lysosomal compartment of vertebrate B-lymphocytes. Eur J Cell Biol. 85, 1253-1264, 2006.

Grubisha O., Rafty L.A., Takanishi C.L., Xu X., Tong L., Perraud A.L., Scharenberg A.M. and Denu J.M.  Metabolite of SIR2 reaction modulates TRPM2 ion channel. J Biol Chem. 281, 14057-14065, 2006.

Sahni J., Nelson B., Scharenberg A.M. SLC41A2 encodes a plasma-membrane Mg2+ transporter. Biochem J. 401, 505-513, 2007.

Volna P., Jarjour J., Baxter S., Roffler S.R., Monnat R.J., Stoddard B.L. and Scharenberg A.M. Flow cytometric analysis of DNA binding and cleavage by cell surface-displayed homing endonucleases. Nucleic Acids Research, 35, 2748-2758, 2007.

Liu P., Scharenberg A.M., Cantrell D.A., Matthews S.A. Protein kinase D enzymes are dispensable for proliferation, survival and antigen receptor-regulated NFkappaB activity in vertebrate B-cells., FEBS Lett. 581, 1377-1382, 2007.
Scharenberg A.M., Humphries L.A., and Rawlings D.J. (2007) Calcium signalling and cell-fate choice in B cells. Nat Rev Immunol. 7, 778-789, 2007.

Song Y., Buelow B., Perraud A.L. and Scharenberg A.M. Development and validation of a cell-based high-throughput screening assay for TRPM2 channel modulators. J Biomol Screen,13, 54-61, 2008.

Sahni J and Scharenberg A.M. TRPM7 ion channels are required for sustained phosphoinositide 3-kinase signaling in lymphocytes. Cell Metab. 8, 84-93, 2008.

Monnat RJ, Jr., Scharenberg AM and Stoddard BL. Progress in engineering homing endonucleases for gene targeting: ten years after structures. Progress in Gene Therapy Volume 3: Autologous and cancer stem cell gene therapy (R. Bertolotti and K. Ozawa, ed.) World Scientific Publishers, 2008.

Buelow B., Song Y., Scharenberg A.M.. The poly(ADP-ribose) polymerase PARP-1 is required for oxidative stress-induced TRPM2 activation in lymphocytes. J Biol Chem. 283, 24571-24583, 2008.

Buelow B. and Scharenberg A.M. Characterization of Parameters Required for Effective Use of Tamoxifen-Regulated Recombination. PLoS ONE. 3, e3264, 2008.

Takeuchi R., Certo M., Caprara M.G., Scharenberg A.M. and Stoddard B.L.. Optimization of in vivo activity of a bifunctional homing endonuclease and maturase reverses evolutionary degradation. Nucleic Acids Res. 37(3):877-890, 2009.

Liu P., Santisteban I., Burroughs L.R., Ochs H.D., Torgerson T.R., Hershfield M.S., Rawlings D.J. and Scharenberg A.M. Immunologic reconstitution during PEG-ADA therapy in an unusual mosaic ADA-deficient patient. Clin Immunol. 130, 162-174, 2009.

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Updated 7/13/09