Judit Perez Ortiz

Ph.D 2016

Member of MSTP (MD/PhD) program

E-mail: [email protected]

Thesis Title:

PKA phosphorylation of ATAXIN1 in Purkinje cells modulates early onset of ataxia

Current Position:

Resident, Research Track; Child Neurology; Mayo Clinic

Previous Position(s):

Postdoctoral Fellow, University of Kansas

Undergraduate Institution and Major:

Universidad de Puerto Rico, B.S. in Biology 2009

Graduate Advisor:

Harry Orr, Ph.D.

Thesis Committee Members:

  • Paul G. Mermelstein, Ph.D., Department of Neuroscience (Chair)
  • H. Brent Clark, M.D./ Ph.D., Department of Laboratory Medicine and Pathology
  • Marija Cvetanovic, Ph.D., Department of Neuroscience
  • Deanna Koepp, PhD, Genetics, Cell Biology, and Development
  • Harry Orr, Ph.D., Department of Laboratory Medicine and Pathology

Description of Graduate Research:

My lab studies the inherited neurodegenerative disease Spinocerebellar Ataxia type 1 (SCA1). The mutation in SCA1 is an abnormal expansion of CAG repeats in the ATXN1 gene, which leads to production of a pathogenic form of the ATXN1 protein with an expanded polyglutamine tract. A novel finding in our lab is that ATXN1-Ser776 phosphorylation modulates ATXN1 toxicity. Glutamine-expanded ATXN1 as well as phosphorylated ATXN1 are more stable, and this is associated with disease. My graduate research has aimed at uncovering cellular pathways that regulate ATXN1 stability. More recently I have been focused on inhibiting ATXN1 phosphorylation to promote protein clearance as a therapeutic approach. 

Techniques I have used in the lab include: western blotting, qPCR, cloning, AAV virus injections via stereotaxic technique, mouse models of disease, immunofluorescence and confocal microscopy, cell culture, slice culture, pharmacology, transfections, laser dissection.

Research Categories:

  • Neurodegenerative Diseases and Neural Injury
  • Neurogenetics

Graduate Level Awards and Honors:

  • NIH/NIHDS National Research Service Award for Individual Predoctoral MD/PhD Fellows (F31), 2014-2016

Graduate Level Publications:

  • Pérez Ortiz JM, Mollema N, Toker N, Adamski CJ, O'Callaghan B, Duvick L, Friedrich J, Walters MA, Strasser J, Hawkinson JE, Zoghbi HY, Henzler C, Orr HT, Lagalwar S. Reduction of protein kinase A-mediated phosphorylation of ATXN1-S776 in Purkinje cells delays onset of Ataxia in a SCA1 mouse model. Neurobiol Dis. 2018;116:93-105.
  • Pérez Ortiz JM, Orr HT. Spinocerebellar ataxia type 1: Molecular mechanisms of neurodegeneration and preclinical studies. Adv Exp Med Biol. 2018;1049:135-145.


  • Yasushi Nakagawa, MD./PhD., Department of Neuroscience
  • Kevin Wickman, Ph.D., Department of Pharmacology
  • Harry Orr, Ph.D., Department of Laboratory Medicine and Pathology

Why Did You Choose MN?

I chose the UMN because of the breadth of the Neuroscience faculty and research opportunities and the reputation for collaborative research here.

Student Mentor and The Best Advice They Gave.

Pick up projects already started by other graduate students to ensure progress. For first year MD/PhD students, my advice is to treat your first year as your last in the lab. Make sure to get a good project to reliably work in that year. Always have a backup project cooking in the back-burner in case the primary project does not pan out. Apply for NRSA as soon as possible, and follow the NIH recommendations for MSTP students. 

Judit Perez Ortiz