Andrew J. Paterson, Ph.D.

Assistant Professor, Division of Endocrinology, Diabetes and Metabolism

Physical Address:
BDB 767
1808 7th Avenue S.
Birmingham, AL 35294

Office Telephone: (205) 975-8510
Fax: (205) 934-4389

Education:
M.Sc. (Chemistry), University of Canterbury, Christchurch, NEW ZEALAND
Ph.D. (Biochemistry),University of Otago, Dunedin, NEW ZEALAND, 1981

Research Experience:
Post-doctoral training at the NIH, Bethesda, MD, (1981-85)
Research Associate ,University of Toronto, Canada, (1985-89)
Assistant Professor, Dept of Medicine, University of Alabama at Birmingham, (1989-present)

Biography:
Native of Christchurch, New Zealand, (b 1951); citizen of the U.S.A.

Postdoctoral Fellowship at the National Cancer Institute in Bethesda, and continued with Dr. Jeffrey Kudlow in Toronto, Canada. As a research associate with Dr. Kudlow, I focused on TGF?/EGF receptor biology. I was then recruited with Dr. Kudlow to the University of Alabama, Birmingham, as research assistant professor in the Division of Endocrinology in 1989 where I have continued my research as co-investigator on Dr. Kudlow’s grants and assisting in the mentoring of 20 graduate students. I am currently principle investigator on 2 NIH grants.

Research Interests:
The research in our laboratory initially focused on the regulation of growth factor gene expression. Studies with the TGF-? gene promoter in cell culture showed how its expression was greatly influenced by glucose levels. Located on the TGF-? promoter were Sp1 recognition sites and we later discovered that the activity of this ubiquitous transcription factor could be modified by glucose and thus involved in the regulation of TGF-?. This glucose-specific modification to Sp1, and also to a multitude of other cytoplasmic and nuclear proteins, involved the addition of O-linked N-Acetylglucosamine (O-GlcNAc) to serine and threonine amino acids. Focusing on this modification, we showed that Sp1 could be degraded by the proteasome, an organelle essential to the cell in removing unwanted proteins, and that the activity of the proteasome was partly dependent on its O-GlcNAc status. We showed with low glucose (AKA, low nutrition), O-GlcNAcylation was reduced and proteasomes became more active. Thus, in times of low nutrition, the cells survival depends on removing proteins involved in cell propagation, such as Sp1, and using muscle as an energy source, accomplished by the proteasome. The importance of O-GlcNAc modification on proteins has directed our attention to the enzyme that adds the O-GlcNAc moiety to proteins, namely, O-GlcNAc transferase (OGT), and the enzyme that removes the modification, nuclear cytoplasmic O-GlcNAcase and acetyltransferase (NCOAT). In a series of studies, we have shown both enzymes are present in a co-repressor complex involving Sin3A, N-CoR, SMRT, and histone deacetylases. This complex is able to control gene transcription depending on certain stimuli such as hormone signaling (like estrogen), nutrient status, and certain stress conditions. We cloned a naturally occurring NCOAT mutant that has the O-GlcNAcase region spliced out of the gene (NCOATgk). When this form of the enzyme is used in cell culture, NCOATgk behaves as a dominant negative O-GlcNAcase, resulting in increased O-GlcNAc levels. When expressed in transgenic mice, specifically to mammary glands, skeletal muscle, or eye lens, tissue growth and development is impaired and can be attributed to reduced proteasome activity. The implications of controlling protein glycosylation opens the path to the treatment of certain diseases.

Abstracts of Funded Research Projects:
NCI RO1CA095021-14S1 Kudlow and Paterson (PI)
Proteasome regulation by O-glycosylation

The laboratory has shown that protein modification with O-linked N-acetylglucosamine (O-GlcNAc) plays a direct role in the function of transcriptional activators and repressors. This modification, which results from glucose metabolism, also modulates the function of the proteasome, the major organelle involved in intracellular degradation of proteins. The chymotryptic activity of 26S proteasomes, but not 20S proteasomes against 4 amino acid peptides (LLVY) is blocked by incubation of the proteasome with O-GlcNAc transferase (OGT). In addition, the ATPase activity of intact proteasomes is blocked by OGT. Physiologically inactivated proteasomes from NRK cells treated with high glucose or glucosamine can be reactivated by recombinant O-GlcNAcase, the enzyme that removes this modification. Labeling studies on purified proteasomes with [3H]-GlcNAc indicate that the modified protein(s) have a molecular mass of about 45 kDa and that this substrate resides in the 19S regulatory cap of the proteasome. Since the proteasome degrades pro-apoptotic factors such as p53 and many of its downstream targets, inhibition of proteasome function might lead to the accumulation of these factors with the induction of apoptosis. The chemotherapeutic agent and GlcNAc analog, streptozotocin, also induces apoptosis through its property as a non-competitive inhibitor of the O-GlcNAcase. The proposed studies are designed to determine the biochemical linkage between the O-GlcNAc pathway and the proteasome. The ability of O-GlcNAc to block proteasomal function may also couple glucose metabolism to amino acid release from muscle wasting. The specific aims are as follows: General goal: Determine the role of O-GlcNAc in proteasomal function. 1. Determine the effect of O-GlcNAc transferase (OGT) and O-GlcNAcase on proteasome function in vitro using these enzymes to reversibly modify proteins in the proteasome in vitro. 2. Identify proteasomeassociated protein(s) that contain the O-GlcNAc modification and regulate proteasome function in a reversible manner. 3. Determine how O-GlcNAcylation of the proteasome 19S regulatory subunit modifies the function of the proteasomal peptidase and ATPases. 4. Using transgenic mice, determine the effect of proteasome blockade in vivo on epithelial cell apoptosis and muscle protein wasting.

NIDDK RO1DK043652-14A1 Kudlow and Paterson (PI)
O-Glycosylation in Breast Cancer

The enzyme, O-GlcNAc transferase (OGT) that modifies nucleocytoplasmic proteins with O-GlcNAc has recently been shown to be part of the co-repressor complex turning off the transcription of genes. OGT associates with mSin3A and, therefore, is involved with genes that bind nuclear hormone receptors when the hormones, like estrogen, are not present. By modifying transcription activators, OGT cooperates with histone deacetylase to shut off transcription at sites where its scaffold, mSin3A, is present. Bound to OGT in a saturable fashion is NCOAT (nuclear cytoplasmic O-GlcNAcase and acetyltransferase), a bifunctional enzyme with O-GlcNAcase and histone acetyltransferase activities. NCOAT, by residing in co-repression complexes, allows the gene to be turned on again when hormone becomes present by reversing the actions of OGT and histone deacetylase. An NCOAT peptide that interacts with OGT, but has no enzymatic activities, blocks the ability of estrogen to induce estrogen-dependent genes or mammary development in transgenic mice. Thus, NCOAT is downstream of hormone and requires activation to reverse the actions of histone deacetylase and OGT. The aims of this project are as follows: 1. Further characterize transgenic mice to determine the role of NCOAT in mammary development and other estrogen actions in the mammary gland. 2. Find where and how NCOAT is modified to activate it and what enzymes are involved. 3. Use the OGT interaction of NCOAT to design peptide therapy for breast cancer. This translational therapy will be developed to treat human breast cancer whose growth has become hormone-independent.

Selected Publications:

  1. Zhang, F., Y. Hu, P. Huang, C. A. Toleman, A. J. Paterson, and J. E. Kudlow. 2007. Proteasome function is regulated by cyclic AMP-dependent protein kinase through phosphorylation of RPT6. J Biol Chem In Press.
  2. Whisenhunt, T. R., X. Yang, D. B. Bowe, A. J. Paterson, B. A. Van Tine, and J. E. Kudlow. 2006. Disrupting the enzyme complex regulating O-GlcNAcylation blocks signaling and development. Glycobiology 16:551-63.
  3. Toleman, C., A. J. Paterson, and J. E. Kudlow. 2006. Location and characterization of the O-GlcNAcase active site. Biochim Biophys Acta 1760:829-39.
  4. Bowe, D. B., A. Sadlonova, C. A. Toleman, Z. Novak, Y. Hu, P. Huang, S. Mukherjee, T. Whitsett, A. R. Frost, A. J. Paterson, and J. E. Kudlow. 2006. O-GlcNAc integrates the proteasome and transcriptome to regulate nuclear hormone receptors. Mol Cell Biol 26:8539-50.
  5. Liu, K., A. J. Paterson, F. Zhang, J. McAndrew, K. Fukuchi, J. M. Wyss, L. Peng, Y. Hu, and J. E. Kudlow. 2004. Accumulation of protein O-GlcNAc modification inhibits proteasomes in the brain and coincides with neuronal apoptosis in brain areas with high O-GlcNAc metabolism. J Neurochem 89:1044-55.
  6. Hu, Y., L. Riesland, A. J. Paterson, and J. E. Kudlow. 2004. Phosphorylation of mouse glutamine: fructose-6-phosphate amidotransferase 2 (GFAT2) by cAMP-dependent protein kinase increases the enzyme activity. J Biol Chem.
  7. Zhang, F., K. Su, X. Yang, D. B. Bowe, A. J. Paterson, and J. E. Kudlow. 2003. O-GlcNAc modification is an endogenous inhibitor of the proteasome. Cell 115:715-25.
  8. Yang, X., K. Su, M. D. Roos, Q. Chang, A. J. Paterson, and J. E. Kudlow. 2001. O-linkage of N-acetylglucosamine to Sp1 activation domain inhibits its transcriptional capability. Proc Natl Acad Sci U S A 98:6611-6.
  9. Su, K., X. Yang, M. D. Roos, A. J. Paterson, and J. E. Kudlow. 2000. Human Sug1/p45 is involved in the proteasome-dependent degradation of Sp1. Biochem J 348 Pt 2:281-9.
  10. Xie, W., X. Wu, L. T. Chow, E. Chin, A. J. Paterson, and J. E. Kudlow. 1998. Targeted expression of activated erbB-2 to the epidermis of transgenic mice elicits striking developmental abnormalities in the epidermis and hair follicles. Cell Growth Differ 9:313-25.
  11. Roos, M. D., W. Xie, K. Su, J. A. Clark, X. Yang, E. Chin, A. J. Paterson, and J. E. Kudlow. 1998. Streptozotocin, an analog of N-acetylglucosamine, blocks the removal of O-GlcNAc from intracellular proteins. Proc Assoc Am Physicians 110:422-32.
  12. Shin, T. H., A. J. Paterson, and J. E. Kudlow. 1995. p53 stimulates transcription from the human transforming growth factor alpha promoter: a potential growth-stimulatory role for p53. Mol Cell Biol 15:4694-701.
  13. Paterson, A. J., and J. E. Kudlow. 1995. Regulation of glutamine:fructose-6-phosphate amidotransferase gene transcription by epidermal growth factor and glucose. Endocrinology 136:2809-16.
  14. McAndrew, J., A. J. Paterson, S. L. Asa, K. J. McCarthy, and J. E. Kudlow. 1995. Targeting of transforming growth factor-alpha expression to pituitary lactotrophs in transgenic mice results in selective lactotroph proliferation and adenomas. Endocrinology 136:4479-88.
  15. Raja, R. H., A. J. Paterson, T. H. Shin, and J. E. Kudlow. 1991. Transcriptional regulation of the human transforming growth factor-alpha gene. Mol Endocrinol 5:514-20.