Karl Willert, Ph.D - Investigator Profile
The main focus of Dr. Karl Willert’s lab is to understand how the extracellular environment regulates cell fate choices. His lab utilizes human pluripotent stem cells—both embryonic and induced pluripotent stem cells (hESC and iPSC)—to explore early developmental fate choices with particular emphasis on the Wnt signaling pathway.
The first Wnt gene was identified by virtue of its over-expression in the mouse mammary gland, thereby contributing to the progression of mammary tumors. Since then, Wnt proteins and their signaling cascades have been studied in a vast number of developmental processes and human cancers. The human genome contains at least 19 distinct Wnt genes whose protein products interact with several cell surface receptors and stimulate a number of signal transduction pathways. A longterm goal of Dr. Willert’s research is to understand how these highly conserved signaling molecules elicit such a breadth of biological outcomes.
In 2003, Dr. Willert successfully purified the first Wnt protein to homogeneity, and demonstrated that one particular Wnt protein, Wnt3a, elicits potent effects on self renewal of blood forming stem cells. Since these discoveries, many labs have interrogated the role of Wnt signaling in a vast variety of tissues, including skin, intestine, liver and brain. The isolation of biologically active and pure Wnt protein enabled the analysis of how Wnt proteins interact with the complex extracellular environment. Importantly, Dr. Willert found that mature Wnt proteins are modified by a covalently attached lipid, a modification that regulates Wnt secretion and distribution in the extra-cellular space.
Presently, Dr. Willert has three main research projects: (i) exploring how Wnt signaling regulates pluripotent stem cell behavior, (ii) applying a cellular microarray technology to interrogate the role of the extracellular microenvironment on stem cell pluripotency and differentiation, and (iii) studying the Wnt signal transduction pathway.
Cell signaling, Cellular Microarray Technology, Extracellular Microenvironment, Human Pluripotent Stem Cells, Microarray, Stem Cells, Wnt, Wnt Signaling