John L. Wang

John Wang is a Professor Emeritus in the Department of Biochemistry and Molecular Biology at Michigan State University in East Lansing, Michigan. He received his undergraduate degree in chemistry from Dartmouth College (Hanover, New Hampshire) and a Ph.D. degree from The Rockefeller University (New York, New York).

Dr. Wang has had a career-long interest in carbohydrate-binding proteins (lectins). His doctoral thesis was on the covalent and three-dimensional structure of the plant lectin, concanavalin A (Con A). During post-doctoral work in the laboratory of Dr. Gerald Edelman, an analysis of the inhibition by Con A of the mobility of lymphocyte surface receptors suggested that the lateral motion and distribution of cell surface receptors are under the control of a submembranous macromolecular assembly, providing one of the first line of evidence of transmembrane receptor-cytoplasmic interactions.

At Michigan State University, his laboratory isolated the first three members of the galectin family as galactose-specific carbohydrate-binding proteins. They reported the interesting phenomenon of dual localization: galectin-3 (Gal3) turned out to be the macrophage cell surface antigen designated as Mac-2 but convincing evidence was also documented that it can found in the nucleus of cells as well. Immunolocalization and cell fractionation experiments revealed Gal3 as a component of ribonucleoprotein complexes with densities (on sedimentation on Cs2SO4 density gradients) corresponding to those reported for hnRNP and snRNP. In collaboration with Dr. Ron Patterson, a colleague on the Michigan State faculty, they showed that Gal3 and another family member, galectin-1 (Gal1), were required but redundant factors for nuclear pre-mRNA splicing in a cell-free assay. Gal3 shuttles between the nucleus and cytoplasm and both a nuclear localization signal, as well as a nuclear export signal, were identified on the polypeptide.