Jan L. Christian

Biography

Cell-cell signaling molecules such as bone morphogenetic proteins (BMPs) play critical roles in specifying cell fate during vertebrate embryogenesis. Strict regulation of BMP activity is required to prevent birth defects, degenerative diseases and cancer. Our research program has two major foci: 1) Understanding how BMP activity is regulated by cleavage of the precursor protein and by interactions with the extracellular matrix. We use targeted mutagenesis in mice together with cell biological and biochemical approaches in Xenopus embryos to determine how cleavages within the inactive prodomain of the BMP precursor protein regulate the activity of mature BMP homodimers and heterodimers. One current project in the lab involves analysis of mice carrying a point mutation that prevents cleavage of BMP7. This cleavage mutant mouse dies early in development due to defects in the heart and other organs that are caused by the combined loss of BMP7 and other BMP family members that normally heterodimerize with BMP7. 2) Analysis of novel proteins that function downstream of BMPs during hematopoeisis and other developmental processes. We have used a microarray based approach to identify multiple novel gene products and signaling pathways that function downstream of BMPs in blood development. One protein of particular interest is a novel transmembrane protein that is required not only for blood formation but also for formation of the central nervous system and other dorsal structures. We are trying to understand how this protein transduces signals from the membrane to the nucleus to control early development.

Research Interest

Bone Morphogenetic Proteins Growth and Embryonic Development Marfan Syndrome Mouse Models Xenopus laevis Proprotein Convertases Cardiovascular Aspects of Marfan syndrome Hematopoiesis Extracellular Matrix