This proposal seeks training for the P.I. in the molecular biology of skin development. The project will take place in the laboratory of Dr. Merton Bernfield at the facilities of the Harvard Medical School and Children's Hospital. The laboratory is an outstanding intellectual environment consisting of 5 Ph.D. and 3 M.D. post-doctorals. A major interest of this laboratory is the cell surface molecule syndecan. Syndecan is a prototype cell surface proteoglycan that binds extracellular matrix and growth factors, molecules that promote differentiation. Mammary epithelial cells made syndecan-deficient change cell morphology, decrease expression of cell adhesion molecules, and have disorganized F-actin. Syndecan is also expressed in a strictly defined pattern at epithelial-mesenchymal junctions during morphogenesis, is highly conserved between species, and exists in tissue type-specific polymorphic forms. Thus, syndecan may play an important role in tissue interaction during development. This proposal is designed to investigate the functions of syndecan in order to further understand epithelial-mesenchymal interactions in development. To accomplish this a structure/function analysis is presented of syndecan. This approach will define selected functions of syndecan by mapping function to specific structural domains. Specifically, this proposal seeks to: (i) Identify and characterize syndecan expression in selected cell types that lack expression of syndecan at the cell surface. (ii) Transfect syndecan and mutant constructs into those cells identified as originally lacking surface expression such that they will now express syndecan or its mutant construct. (iii) Analyze functional response in terms of cell morphology, matrix adhesion, cell-cell adhesion, cell motility, and bFGF binding and activity in appropriate transfectants, thus identifying structure- function relationships. Completion of these studies will provide the P.I. with investigative skills in molecular and developmental biology. This training will permit the P.I. to continue his career as an independent investigator working on problems relevant to growth and development of the skin.
