2003-present Professor, University of Notre Dame 1992-2003 Associate Professor, University of Notre Dame 1985-1992 Assistant Professor, University of Notre Dame 1982-1985 Research Associate, University of Chicago 1979-1982 Postdoctoral Fellow, University of Chicago 1978- Ph.D. in Biochemistry, Purdue University 1973 B.S. in Biology & Chemistry, Boston College Award: 2001 Kaneb Teaching Award 1987-1992 FIRST Award, National Institutes of Health 1979-1981 Postdoctoral Fellowship, National Institutes of Health

Biochemistry

Several important events transpire in Xenopus oocytes that determine proper development during embryogenesis. Because there is no transcription during the rapid cell division cycles of early embryogenesis, the oocyte must stockpile large amounts of ribosomes to support the demands of protein synthesis during the period following fertilization. There are two types of genes that encode 5S ribosomal RNA. One, the somatic-type, is transcribed at all stages of development, while the other, the oocyte-type, is only transcribed during oogenesis and early embryogenesis. Thus, the differential expression of these genes provides a good model system for studying the developmental control of transcription. The principal regulator of 5S rRNA gene transcription is TFIIIA. We have found that this transcription factor becomes phosphorylated and SUMOylated at key times during development. These modifications apparently change the expression pattern of the 5S rRNA genes. The goal of this work is to understand these events at the molecular level.

The body plan of the frog begins to be determined in the unfertilized oocyte. The localization of some crucial mRNAs to specific regions of this single cell is a major mechanism that underlies proper development during embryogenesis. One mRNA, Vg1, encodes a member of the TGF-β family and is localized to the vegetal cortex of the mature oocyte. We have identified several proteins that bind to the region of Vg1 mRNA that determines its localization and translational control. Currently, our aim is to determine the role of each factor in localization, how these proteins interact and work together in this process, and to identify other components of the mRNA localization pathway.

Ghose R., Malik M. and Huber, P.W. (2004) "Restricted Specificity of Xenopus TFIIIA for Transcription of Somatic 5S rRNA Genes" Mol. Cell. Biology, 24(6) 2467-2477. DiNitto, J.P. and Huber, P.W. (2003) "Mutual Induced Fit Binding of Xenopus Ribosomal Protein L5 to 5S rRNA" J. Mol. Biol. (PDF) Kolev, N. G. and Huber P.W. (2003) "VgRBP71 Stimulates Cleavage at a Polyadenylation Signal in Vg1 mRNA, Resulting in the Removal of a Cis-acting Element that Represses Translation" Mol. Cell 11, 745-755. (PDF) Kroll, T. T., Zhao, W.-M., Jiang, C.,and Huber P.W. (2002) "A Homolog of FBP2/KSRP Binds to Localized mRNAs in Xenopus Oocytes" Development 129, 5609-5619. (PDF) Westmark, C. J., Ghose R., and Huber P.W. (2002) "Phosphorylation of Xenopus Transcription Factor IIIA by an Oocyte Protein Kinase CK2" Biochem. J. 362, 375-382. (PDF) DiNitto, J. P. and Huber P.W. (2001) "A Role for Aromatic Amino Acids in the Binding of Xenopus Ribosomal Protein L5 to 5S rRNA" Biochemistry 40, 12645-12653. (PDF) Zhao, W.-M., Jiang, C., Kroll, T.T., and Huber P.W. (2001) "A Proline-rich Protein Binds to the Localization Element of Xenopus Vg1 mRNA and to Ligands Involved in Actin Polymerization" EMBO J. 20, 2315-2325. (PDF) Huber, P. W., Rife, J.P. and Moore, P.B. (2001) "The Structure of Helix III in Xenopus Oocyte 5S rRNA: An RNA Stem Containing a Two-Nucleotide Bulge" J. Mol. Biol. 312, 823-832. (PDF)