Mammary epithelial cells transition between periods of proliferation and quiescence during development, menstrual cycles, and pregnancy, and as a result of oncogenic transformation. Utilizing an organotypic 3D tissue culture model coupled with quantitative metabolomics and proteomics, we identified significant differences in glutamate utilization between proliferating and quiescent cells. Relative to quiescent cells, proliferating cells catabolized more glutamate via transaminases to couple non-essential amino acid (NEAA) synthesis to alpha-ketoglutarate generation and tricarboxylic acid (TCA) cycle anaplerosis. As cells transitioned to quiescence, glutamine consumption and transaminase expression were reduced, while glutamate dehydrogenase (GLUD) was induced, leading to decreased NEAA synthesis. Highly proliferative human tumors display high transaminase and low GLUD expression, suggesting that proliferating cancer cells couple glutamine consumption to NEAA synthesis to promote biosynthesis. These findings describe a competitive and partially redundant relationship between transaminases and GLUD, and they reveal how coupling of glutamate-derived carbon and nitrogen metabolism can be regulated to support cell proliferation.
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Csibi, Alfred
;
Fendt, Sarah-Maria
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Chem Engn, Cambridge, MA 02139 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Fendt, Sarah-Maria
;
Li, Chenggang
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Li, Chenggang
;
Poulogiannis, George
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Beth Israel Med Ctr, Div Signal Transduct, Boston, MA 02115 USA
Harvard Univ, Sch Med, Dept Syst Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Poulogiannis, George
;
Choo, Andrew Y.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Choo, Andrew Y.
;
Chapski, Douglas J.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Chapski, Douglas J.
;
论文数: 引用数:
h-index:
机构:
Jeong, Seung Min
;
Dempsey, Jamie M.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Dempsey, Jamie M.
;
Parkhitko, Andrey
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Parkhitko, Andrey
;
Morrison, Tasha
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Morrison, Tasha
;
Henske, Elizabeth P.
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Henske, Elizabeth P.
;
Haigis, Marcia C.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Haigis, Marcia C.
;
Cantley, Lewis C.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Beth Israel Med Ctr, Div Signal Transduct, Boston, MA 02115 USA
Harvard Univ, Sch Med, Dept Syst Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Cantley, Lewis C.
;
Stephanopoulos, Gregory
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Chem Engn, Cambridge, MA 02139 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Stephanopoulos, Gregory
;
Yu, Jane
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Yu, Jane
;
Blenis, John
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Lee, Gina
;
Yoon, Sang-Oh
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Yoon, Sang-Oh
;
Tong, Haoxuan
论文数: 0引用数: 0
h-index: 0
机构:
Dana Farber Canc Inst, Dept Canc Biol, Boston, MA 02115 USA
Harvard Univ, Sch Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Tong, Haoxuan
;
Iiter, Didem
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Weill Cornell Med Coll, Meyer Canc Ctr, Dept Pharmacol, New York, NY 10065 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Iiter, Didem
;
Elia, Ilaria
论文数: 0引用数: 0
h-index: 0
机构:
Flemish Inst Biotechnol VIB, Vesalius Res Ctr, B-3000 Leuven, Belgium
KU Leuven Univ Leuven, Dept Oncol, B-3000 Leuven, BelgiumHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Elia, Ilaria
;
Fendt, Sarah-Maria
论文数: 0引用数: 0
h-index: 0
机构:
Flemish Inst Biotechnol VIB, Vesalius Res Ctr, B-3000 Leuven, Belgium
KU Leuven Univ Leuven, Dept Oncol, B-3000 Leuven, BelgiumHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Fendt, Sarah-Maria
;
论文数: 引用数:
h-index:
机构:
Roberts, Thomas M.
;
Blenis, John
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Weill Cornell Med Coll, Meyer Canc Ctr, Dept Pharmacol, New York, NY 10065 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
DeNicola, Gina M.
;
Chen, Pei-Hsuan
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Chen, Pei-Hsuan
;
Mullarky, Edouard
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Mullarky, Edouard
;
Sudderth, Jessica A.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Sudderth, Jessica A.
;
Hu, Zeping
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Hu, Zeping
;
Wu, David
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Wu, David
;
Tang, Hao
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Dept Clin Sci, Quantitat Biomed Res Ctr, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Tang, Hao
;
Xie, Yang
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Dept Clin Sci, Quantitat Biomed Res Ctr, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Xie, Yang
;
Asara, John M.
论文数: 0引用数: 0
h-index: 0
机构:
Beth Israel Deaconess Med Ctr, Dept Med, Div Signal Transduct, Boston, MA 02215 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Asara, John M.
;
Huffman, Kenneth E.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Hamon Ctr Therapeut Oncol, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Huffman, Kenneth E.
;
Wistuba, Ignacio I.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas MD Anderson Canc Ctr, Dept Translat Mol Pathol, Houston, TX 77030 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Wistuba, Ignacio I.
;
Minna, John D.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Hamon Ctr Therapeut Oncol, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Minna, John D.
;
DeBerardinis, Ralph J.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
DeBerardinis, Ralph J.
;
Cantley, Lewis C.
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
机构:
Beth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA
Harvard Univ, Sch Med, Syst Biol Dept, Boston, MA 02115 USABeth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA
Dibble, Christian C.
;
Manning, Brendan D.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Publ Hlth, Dept Genet & Complex Dis, Boston, MA 02115 USABeth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Csibi, Alfred
;
Fendt, Sarah-Maria
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Chem Engn, Cambridge, MA 02139 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Fendt, Sarah-Maria
;
Li, Chenggang
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Li, Chenggang
;
Poulogiannis, George
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Beth Israel Med Ctr, Div Signal Transduct, Boston, MA 02115 USA
Harvard Univ, Sch Med, Dept Syst Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Poulogiannis, George
;
Choo, Andrew Y.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Choo, Andrew Y.
;
Chapski, Douglas J.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Chapski, Douglas J.
;
论文数: 引用数:
h-index:
机构:
Jeong, Seung Min
;
Dempsey, Jamie M.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Dempsey, Jamie M.
;
Parkhitko, Andrey
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Parkhitko, Andrey
;
Morrison, Tasha
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Morrison, Tasha
;
Henske, Elizabeth P.
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Henske, Elizabeth P.
;
Haigis, Marcia C.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Haigis, Marcia C.
;
Cantley, Lewis C.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Beth Israel Med Ctr, Div Signal Transduct, Boston, MA 02115 USA
Harvard Univ, Sch Med, Dept Syst Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Cantley, Lewis C.
;
Stephanopoulos, Gregory
论文数: 0引用数: 0
h-index: 0
机构:
MIT, Dept Chem Engn, Cambridge, MA 02139 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Stephanopoulos, Gregory
;
Yu, Jane
论文数: 0引用数: 0
h-index: 0
机构:
Brigham & Womens Hosp, Dept Med, Div Pulm & Crit Care Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Yu, Jane
;
Blenis, John
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Lee, Gina
;
Yoon, Sang-Oh
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Yoon, Sang-Oh
;
Tong, Haoxuan
论文数: 0引用数: 0
h-index: 0
机构:
Dana Farber Canc Inst, Dept Canc Biol, Boston, MA 02115 USA
Harvard Univ, Sch Med, Boston, MA 02115 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Tong, Haoxuan
;
Iiter, Didem
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Weill Cornell Med Coll, Meyer Canc Ctr, Dept Pharmacol, New York, NY 10065 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Iiter, Didem
;
Elia, Ilaria
论文数: 0引用数: 0
h-index: 0
机构:
Flemish Inst Biotechnol VIB, Vesalius Res Ctr, B-3000 Leuven, Belgium
KU Leuven Univ Leuven, Dept Oncol, B-3000 Leuven, BelgiumHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Elia, Ilaria
;
Fendt, Sarah-Maria
论文数: 0引用数: 0
h-index: 0
机构:
Flemish Inst Biotechnol VIB, Vesalius Res Ctr, B-3000 Leuven, Belgium
KU Leuven Univ Leuven, Dept Oncol, B-3000 Leuven, BelgiumHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Fendt, Sarah-Maria
;
论文数: 引用数:
h-index:
机构:
Roberts, Thomas M.
;
Blenis, John
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
Weill Cornell Med Coll, Meyer Canc Ctr, Dept Pharmacol, New York, NY 10065 USAHarvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
DeNicola, Gina M.
;
Chen, Pei-Hsuan
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Chen, Pei-Hsuan
;
Mullarky, Edouard
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Mullarky, Edouard
;
Sudderth, Jessica A.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Sudderth, Jessica A.
;
Hu, Zeping
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Hu, Zeping
;
Wu, David
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Wu, David
;
Tang, Hao
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Dept Clin Sci, Quantitat Biomed Res Ctr, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Tang, Hao
;
Xie, Yang
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Dept Clin Sci, Quantitat Biomed Res Ctr, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Xie, Yang
;
Asara, John M.
论文数: 0引用数: 0
h-index: 0
机构:
Beth Israel Deaconess Med Ctr, Dept Med, Div Signal Transduct, Boston, MA 02215 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Asara, John M.
;
Huffman, Kenneth E.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Hamon Ctr Therapeut Oncol, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Huffman, Kenneth E.
;
Wistuba, Ignacio I.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas MD Anderson Canc Ctr, Dept Translat Mol Pathol, Houston, TX 77030 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Wistuba, Ignacio I.
;
Minna, John D.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Hamon Ctr Therapeut Oncol, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
Minna, John D.
;
DeBerardinis, Ralph J.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Texas SW Med Ctr Dallas, Childrens Med Ctr, Res Inst, Dallas, TX 75390 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
DeBerardinis, Ralph J.
;
Cantley, Lewis C.
论文数: 0引用数: 0
h-index: 0
机构:
Weill Cornell Med Coll, Dept Med, New York, NY 10065 USAWeill Cornell Med Coll, Dept Med, New York, NY 10065 USA
机构:
Beth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA
Harvard Univ, Sch Med, Syst Biol Dept, Boston, MA 02115 USABeth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA
Dibble, Christian C.
;
Manning, Brendan D.
论文数: 0引用数: 0
h-index: 0
机构:
Harvard Univ, Sch Publ Hlth, Dept Genet & Complex Dis, Boston, MA 02115 USABeth Israel Deaconess Med Ctr, Div Signal Transduct, Boston, MA 02215 USA