 Perry J. BlackshearAdjunct Professor of Biochemistry, Consulting Professor of Medicine, and Director of Clinical Research, NIEHSStudies in polypeptide hormone interaction. Contact InformationTelephone: (919) 541-4899 Fax: (919) 541-4571 e-mail black009@niehs.nih.gov Building 101 NIEHS 111 Alexander Drive RTP NC 27709 Clinical Res NIEHS PO Box 12233 RTP, NC 27709 Education
Research InterestsOur laboratory has been interested in several aspects of signal transduction resulting from binding of polypeptide hormones to their surface receptors on cells. One major topic under study is the role of direct substrates for protein kinase C (PKC) in mediating the many cellular effects resulting from activation of this family of kinases by hormones and other agonists. We have been studying a small family of PKC subtrates consisting of MARCKS and its smaller homologue, the MARCKS-like protein or MLP. Current ongoing projects include structure function studies of the proteins and their mutant derivatives in two major systems, development of the mouse central nervous system, and early embryogenesis in Xenopus laevis. We are also studying promoter elements in these two species to determine which elements are important for the developmentally regulated, tissue-specific and cytokine-induced expression of these genes. We are investigating potential interactions of these proteins with a protease that specifically cleaves MARCKS,cathepsin B, and potential roles of these interactions in growth and metastasis of certain tumors, especially human breast cancer. Finally, we are investigating the possibility that mutations in the MARCKS and MLP genes are involved in the development of human neural tube defects and congenital forms of muscular dystrophy. A second major area of study in the laboratory began with the cloning of a gene that was rapidly and massively induced by insulin. The protein encoded by this gene, known as TTP, is the prototype of a novel class of CCCH zinc finger proteins, of which three have been identified in mammalian systems. We have shown in the past that TTP is rapidly induced, translocated from the nucleus to the cytosol, and phosphorylated on serine residues by insulin and by many other mitogens and growth factors. In an attempt to elucidate a function for this class of proteins, we created mice deficient in TTP. They develop a complex syndrome consisting of arthritis, wasting, dermatitis, and early death; more recent work has identified TNF alpha excess as the cause of most if not all aspects of the syndrome. We have shown that TNF is overproduced by macrophages derived from these knockout mice, and that the syndrome can be transplanted with whole marrow transplantation into mice. More recently, we found that TTP, as well as its two related proteins, can bind to a portion of the TNF alpha mRNA called the AU-rich element, and in some way make this mRNA unstable. Similar findings were observed with the mRNA encoding the granulocyte-macrophage colony stimulating factor (GM-CSF). Current studies are trying to identify the mechanism by which TTP acts to cause more rapid destruction of the TNF and GM-CSF mRNA; to further refine the TTP gene promoter elements involved in the rapid mitogen-stimulated expression of the gene; to identify TTP’s binding partner(s), in the hope of finding modulators of its activities; and to knock-out the two known mammalian relatives of TTP in the hope of developing other informative phenotypes. Recent Publications1. Lai, W.S., Carballo, E., Thorn, J.M., Kennington, E.A. and Blackshear, P.J. (2000) Interactions of CCCH zinc finger proteins with mRNA. 1. Binding of tristetraprolin-related zinc finger proteins to AU-rich elements and destabilization of mRNA. J. Biol. Chem., 275:17827-19837. More… 2. Carballo, E., Lai, W.S. and Blackshear, P.J. (2000) Evidence that tristetraprolin (TTP) is a physiological regulator of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA deadenylation and stability. Blood 95:1891-1899. More… 3. Carballo, E, Pitterle, DM, Stumpo, DJ, Sperling, RT and Blackshear, PJ. (1999) Phagocytic and/or macropinocytic activity in MARCKS-deficient macrophages and fibroblasts. Am. J. Physiol. 277:C163-C173. More… 4. Lai, WS, Carballo,E, Strum, JS, Kennington, EA, Phillips, RS and Blackshear, PJ. (1999) Evidence that tristetraprolin (TTP) binds to AU-rich elements and promotes the deadenylation and destabilization of tumor necrosis factor a mRNA. Mol. Cell. Biol. 19:4311-4323. More… 5. De, J, Lai, WS, Thorn, JM, Goldsworthy, SM, Liu, X, Blackwell, TK and Blackshear, PJ. (1999) Identification of four CCCH zinc finger proteins in Xenopus, including a novel vertebrate protein with four zinc fingers and severely restricted expression. Gene 228: 133-145. More… 6. Lai WS, Thompson MJ and Blackshear PJ. (1998) Characteristics of the intron involvement in the mitogen-induced expression of Zfp-36. J. Biol. Chem. 273:506-517. More… 7. Kim HS, Swierczynski SL, Tuttle JS, Lai WS and Blackshear PJ. (1998) Transgenic complementation ofMARCKS deficiency with a non-myristoylatable, pseudo-phosphorylated form of MARCKS: Evidence for simultaneous positive and dominant-negative effects on central nervous system development. Devel. Biol. 200:146-157. More… 8. Stumpo DJ, Eddy RL, Jr., Haley LL, Sait S, Shows TB, Lai WS, Young WS III, Speer MC, Dehijia A, Polymeropoulos M and Blackshear PJ. (1998) Promoter sequence, expression and fine chromosomal mapping of the human gene (MLP) encoding the MARCKS-like protein: Identification of neighboring and linked polymorphic loci for MLP and MACS and use in the evaluation of human neural tube defects. Genomics 49:253-264. More… 9. Carballo E, Lai, WS and Blackshear PJ. (1998) Feedback inhibition of macrophage tumor necrosis factor a production by tristetraprolin. Science 281:1001-1005. More… 10. McNamara, RK, Stumpo, DJ, Morel, LM, Lewis, MH, Wakeland, EK, Blackshear, PJ and Lenox, RH. (1998) Effect of reduced myristoylated alanine-rich C kinase substrate expression on hippocampal mossy fiber development and spatial learning in mutant mice: Transgenic rescue and interactions with gene background. Proc. Natl. Acad. Sci. USA 95: 14517-14522. More… 11. McNamara, RK, Stumpo, DJ, Morel, LM, Lewis, MH, Wakeland, EK, Blackshear, PJ and Lenox, RH. (1998) Effect of reduced myristoylated alanine-rich C kinase substrate expression on hippocampal mossy fiber development and spatial learning in mutant mice: Transgenic rescue and interactions with gene background. Proc. Natl. Acad. Sci. USA 95: 14517-14522. More… 12. Carballo, E, Gilkeson, GS and Blackshear, PJ (1997). Bone marrow transplantation reproduces the tristetraprolin-deficiency syndrome in recombination activating gene-2 ( 13. Spizz, G and Blackshear, PJ (1997). Identification and characterization of cathepsin B as the cellular MARCKS cleaving enzyme. J. Biol. Chem., 272: 23784-23842. More… 14. Shi Y, Sullivan SK, Pitterle DM, Kennington EA, Graff JM, Blackshear PJ. (1997) Mechanismsof MARCKS gene activation during Xenopus development. J. Biol. Chem. 272: 29290-29300. More… 15. Taylor, GA, Carballo, E, Lee, DM, Lai, WS, Thompson, MJ, Patel, DD, Schenkman, DI, Gilkeson, GS, Broxmeyer, HE, Haynes, BF and Blackshear, PJ (1996). A pathogenetic role for TNF alpha in the syndrome of cachexia, arthritis, and autoimmunity resulting from tristetraprolin (TTP) deficiency. Immunity 4:445-454. More… 16. Swierczynski, SL and Blackshear, PJ (1996) Myristoylation-dependent and electrostatic interactions exert independent effects on the membrane association of the myristoylated alanine-rich protein kinase C substrate protein in intact cells. J. Biol. Chem. 271:23424-23430. More… 17. Blackshear, PJ, Lai, WS, Tuttle, JS, Stumpo, DJ, Kennington, E, Nairn, AC and Sulik, KK (1996). Developmental expression of MARCKS and protein kinase C in mice in relation to the exencephaly resulting from MARCKS deficiency. Devel. Brain Res. 96:62-75. More… 18. Swierczynski, SL, Siddhanti, SR, Tuttle, JS and Blackshear, PJ (1996) Nonmyristoylated MARCKS complements some but not all of the developmental defects associated with MARCKS deficiency in mice Devel. Biol. 179:135-147. More… |
|
