Dr. Banerjee is a professor and the chair of the Molecular, Cell, and Developmental Biology Department at UCLA, of which he has been a part since 1988. He has a joint appointment in the Department of Biological Chemistry. He teaches introductory and advanced genetics courses to undergraduate and graduate students. Dr. Banerjee is among 20 professors nationally to be awarded a $1 million grant by the Howard Hughes Medical Institute (HHMI) to creatively improve undergraduate science teaching. The grant has generously funded the UCLA Undergraduate Research Consortium in Functional Genomics (URCFG).

Intercellular interactions play a pivotal role in the development of the nervous system of all organisms. Recent studies have suggested that many aspects of cell-cell interactions involve common pathways for signal transduction. Members of such cascades include cellular oncogenes, whose malfunction can cause misregulation of growth and development. Our laboratory uses the developing eye of Drosophila as a model system since in this system, complex interactions between signal transduction pathways can be resolved into simpler genetic pathways. Work in our laboratory, and that of others has demonstrated that many of these pathways include Drosophila homologs of vertebrate oncogenes. The Son of sevenless (Sos) gene, first identified by mutational analysis in our laboratory has been found to be a link between tyrosine kinase receptors and Ras in many signaling systems across species. A significant aspect of our research also focuses on transcription factors that provide the context in which signaling cascades are interpreted. It is well known that a Ras derived signal could either cause a cell to divide or differentiate depending upon its predisposition. We have found that a transcription factor homologous to the Acute Myeloid leukemia (AML1) gene product in humans is important in allowing cells in the eye and in the hematopoietic system to interpret signals that they receive. It seems that developmental decisions involve a small number of signal transduction pathways, the outputs from which are interpreted combinatorially by the enhancer sequences of downstream genes. Our laboratory would like to understand how different signal transduction cascades are integrated to produce unique developmental responses.

The first developmental systems that we concentrate on is the eye, where we are identifying novel means by which different signal transduction cascades combine to distinguish between neural and non-neural cell types. the second is hematopoiesis, where we have found that molecules similar to GATA and AML1 proteins are critically needed. Much as the stromal cell layer induces hematopoiesis in mammalian systems, we find that a source of Notch signaling in a small number of cells is critical for the maintenance of one of the hematopoietic precursors in Drosophila. Through these studies, using Drosophila as a genetic model, we hope to identify basic molecular strategies that are conserved in development across species.