Daniel Donoghue

Affiliation: UCSD Biochem.

Professor, Department of Chemistry and Biochemistry

Biography

B.S. University of Wisconsin, Madison, 1974;
Ph.D. Massachusetts Institute of Technology, 1979;
Phi Kappa Phi Graduate Fellowship, 1974-1975;
Health Sciences Fund Fellowship, 1977-1979;
Postdoctoral Fellow, Salk Institute, 1980-1982;
Helen Hay Whitney Fellowship, 1980-1982;
Appointed to faculty 1982-;
Searle Scholars Fellowship, 1983-1986;
Recipient of American Cancer Society Faculty Research Award, 1989-1993.

Research Summary

Research Areas: FGFR3 signaling in human cancer; RTKs; FRET imaging; FGFRs in developmental syndromes; cell cycle regulation; ptc1; DNA damage; cyclin B1; tuberin.

1 - FGFR3 INVOLVEMENT IN HUMAN CANCER
The FGFR (fibroblast growth factor receptor) family of receptor tyrosine kinases is important for cell growth, differentiation, migration, wound healing and angiogenesis. Many different human developmental syndromes are due to mutations in one of the four related FGFRs. FGFR3 mutations are responsible for the common form of human skeletal dwarfism and also the neonatal lethal syndrome, Thanatophoric Dysplasia. In addition, activating mutations in FGFR3 have been identified which contribute to the progression of human carcinomas. In approximately 25% of patients with multiple myeloma (MM), an invariably fatal B-cell malignancy that accounts for about 10% of hematopoietic cancers, several of these same FGFR3 mutations have been found to occur. We recently demonstrated a novel interaction between FGFR3 and another important regulatory protein, Pyk2/RAFTK, which has been shown to regulate scheduled cell death of MM cells. Along these lines we will explore the molecular mechanism whereby FGFR3 contributes to the cancerous properties of MM cells, possibly through Pyk2.

2 - REGULATION OF RECEPTOR TYROSINE KINASES
Receptor tyrosine kinases (RTKs) represent an important group of signaling molecules involved in the transmission of information across the membrane of the cell. Mutations in RTKs contribute towards significant human developmental and neoplastic syndromes, including breast cancer (Neu/ErbB2), skeletal dwarfism (FGFR3), gastrointestinal stromal tumors and mastocytoma (KIT), and multiple endocrine neoplasia type 2A and familial medullary thyroid carcinoma (RET). We are examining the role of the transmembrane domain in regulating the activity of these RTKs, as well as the mechanism which leads to receptor activation and downstream signal transduction. To determine whether rotational coupling for FGFR3, KIT and RET accompanies ligand-stimulated RTK activation, we will employ protein fragment complementation and fluorescence resonanceenergy transfer (FRET).

3 - FGFR2 MUTATIONS IN HUMAN DEVELOPMENTAL SYNDROMES
Human development is exquisitely sensitive to mutations that lead to aberrant signaling through FGFR2, resulting in a variety of autosomal dominant craniosynostosis syndromes and skeletal dwarfism syndromes such as Crouzon Syndrome, Jackson-Weiss Syndrome, Pfeiffer Syndrome, Apert Syndrome, Antley-Bixler Syndrome and Beare- Stevenson Syndrome. Our lab has contributed to understanding the underlying cell biological consequences of these mutations, and we will continue the molecular dissection of these syndromes, focusing on different mechanisms of receptor activation. These studies will advance our understanding of FGFR2-mediated signaling and aberrant RTK activation, which will be of broad relevance in elucidating the molecular and developmental consequences of mutations in other members of the RTK superfamily, as well as in contributing towards the design of potential therapeutic strategies.

4 - BASIC MECHANISMS OF CELL CYCLE REGULATION
Our lab has worked many years towards understanding regulatory proteins involved in mammalian cell cycle regulation. Currently, our studies focus on regulation of the G2/M cyclin, cyclin B1. Together with its kinase binding partner cdk1, cyclin B1 is the universal regulator of progression into mitosis in higher eukaryotes. We have demonstrated that phosphorylation of cyclin B1 targets the cyclin B1-cdk1 complex to the nucleus and initiates the onset of mitosis. We have also shown that patched1 (ptc1), a tumor suppressor, interacts with cyclin B1 to regulate its localization, revealing a significant biochemical interaction involved in the tumor suppressor activity of ptc1. Recently, we discovered an entirely novel cell cycle regulatory protein, designated Spy1, notable for inducing rapid meiotic maturation of Xenopus oocytes, as well as binding to and prematurely activating the G1/S kinase cdk2. We are examining the cell cycle regulatory properties of Spy1, including its ability to activate cdk2, its putative ability to target the cell cycle inhibitor p27Kip1 for increased degradation, and its participation in DNA damage responses. Additionally, we will study the role of spy1 in Xenopus embryogenesis and mammalian development, involving creation of a conditional Spy1 knockout mouse. Another tumor suppressor that communicates biochemically with cyclin B1 is tuberin. Loss of tuberin (or hamartin), leads to abnormal cellular proliferation, resulting in Tuberous Sclerosis. We have detected a direct interaction between tuberin and cyclin B1. These results suggest that in a normal cell, tuberin and cyclin B1 interact before the cell can enter mitosis. This checkpoint may represent a critical regulatory event that is lost in Tuberous Sclerosis. Our goal is to characterize this tuberin/cyclin B1 interaction and determine its biological significance.

References

References From PubMed (NCBI)