Fred Robinson, Ph.D.
After completeing undergraduate work in Biology and Genetics at Oregon State University, Robinson earned a master's degree in Biological Sciences from the University of Nebraska-Lincoln. In 2002, he received his Ph.D. in Biochemistry from The University of Texas Southwestern Medical Center at Dallas and did postdoctoral research at the University of California, San Diego, where he received an NIH-NINDS Pathway to Independence Award in 2007. Robinson joined the Jungers Center as an assistant scientist and assistant professor of Neurology in August 2009. He holds a joint appointment in the Vollum Institute.
Summary of Current Research
The overall goal of our research is to determine how disturbances in phosphoinositide signaling lead to cellular dysfunction and human disease. Mutations in phosphoinositide (PI) phosphatases cause a number of human neurological diseases, including conditions affecting the central and peripheral nervous systems. For example, mutations in several members of the myotubularin family of PI 3-phosphatases lead to Charcot-Marie-Tooth (CMT) peripheral neuropathy, one of most common inherited neurological disorders, which affects about 1 in 2500 worldwide. CMT causes progressive degeneration of muscles in the extremities as well as loss of sensory function.
We are investigating how mutations in members of the myotubularin family of PI 3-phosphatases disrupt PI signaling, and thus cause alterations in endosomal-lysosomal membrane trafficking that lead to peripheral neuropathy. In addition, we are investigating the functions of phosphoinositide signaling in the central nervous system. Myotubularin PI 3-phosphatases specifically dephosphorylate PtdIns3P and PtdIns(3,5)P2, two PIs that regulate membrane traffic within the endosomal-lysosomal pathway. Mutations in the genes for either myotubularin related protein 2 (MTMR2) or MTMR13 cause type 4B CMT (CMT4B), a severe form of the disease characterized by abnormal myelin sheaths and secondary axonal degeneration.
Our work will provide novel insights into how dysregulation of PtdIns3P and PtdIns(3,5)P2 leads to cellular dysfunction and neurological disease. This work also has the potential to lead to therapies for peripheral neuropathies and other diseases of myelin. Understanding how the Schwann cell endosomal-lysosomal pathway is altered by the dysregulation of 3-phosphoinositides is critical to the design of an appropriate pharmacological intervention in CMT4B. In addition, the identification of downstream targets of Mtmr2-Mtmr13 may allow us to define novel signaling pathways, both in the peripheral and central nervous system.
Logan AM, Mammel AE, Robinson DC, Chin AL, Condon AF, Robinson FL. (2017) Schwann cell-specific deletion of the endosomal PI 3-kinase Vps34 leads to delayed radial sorting of axons, arrested myelination, and abnormal ErbB2-ErbB3 tyrosine kinase signaling. Glia [Jun 15: Epub ahead of print].
Ng AA, Logan AM, Schmidt EJ, Robinson FL. (2013) The CMT4B disease-causing phosphatases Mtmr2 and Mtmr13 localize to the Schwann cell cytoplasm and endomembrane compartments, where they depend upon each other to achieve wild-type levels of protein expression. Human Mol. Genet. 22:1493-1506.
Jean S, Cox S, Schmidt EJ, Robinson FL, Kiger A. (2012) Sbf/MTMR13 coordinates PI(3)P and Rab21 regulation in endocytic control of cellular remodeling. Mol. Biol. Cell. 23:2723-2740.
Robinson FL, Niesman IR, Beiswenger KK, Dixon JE. (2008) Loss of the inactive myotubularin-related phosphatase Mtmr13 leads to a Charcot-Marie-Tooth 4B2-like peripheral neuropathy in mice. Proc. Natl. Acad. Sci. USA. 105:4916-4921.
Robinson FL and Dixon JE. (2006) Myotubularin phosphatases: Policing 3-phosphoinositides. Trends Cell Biol. 16:403-412.
Robinson FL and Dixon JE. (2005) The phosphoinositide-3-phosphatase MTMR2 associates with MTMR13, a membrane-associated pseudophosphatase also mutated in type 4B Charcot-Marie-Tooth disease. J. Biol. Chem. 280:31699-31707.