Author Type

Graduate Student

Date of Award

Spring 4-23-2026

Document Type

Dissertation

Publication Status

Version of Record

Submission Date

May 2026

Department

Biological Sciences

College Granting Degree

Charles E. Schmidt College of Science

Department Granting Degree

Biological Sciences

Degree Name

Doctor of Philosophy (PhD)

Thesis/Dissertation Advisor [Chair]

Ryohei Yasuda

Thesis/Dissertation Co-Chair

Robert W. Stackman Jr.

Abstract

Protein kinases regulate cellular function through reversible phosphorylation that coordinates signaling across molecular and cellular scales that influence behavior. Although defining isoform-specific kinase functions is essential for both basic biology and medicine, determining when and where a particular isoform is required remains challenging, especially in behaving animals.

To address this limitation, we developed a Light-Operated Kinase Inhibitor (LOKI) strategy that enables molecular specificity with temporal control. Specificity is achieved by genetically tagging endogenous kinase isoforms, while temporal precision is provided by light-dependent and reversible recruitment of an inhibitory module to the tagged kinase. We engineered and characterized LOKI variants targeting two Protein Kinase C (PKC) isoforms implicated in learning and memory and historically difficult to inhibit selectively: PKCα and PKCδ. Quantitative characterization and in vitro application of LOKI-PKCα demonstrated robust, reversible, isoform-specific inhibition and established LOKI as a potentially generalizable kinase inhibition platform. Using LOKI-PKCα in vitro, we found that transient PKCα activity during the induction phase of synaptic plasticity is required for structural long-term potentiation.

Extending this approach in vivo, acute PKCα inhibition in the medial prefrontal cortex (mPFC) impaired formation of auditory sensorimotor association. Complementary experiments in PKCα knockout mice revealed similar behavioral deficits, and region-specific re-expression of PKCα in the mPFC rescued this impairment. Together, these findings demonstrate a temporally and regionally restricted requirement for PKCα in synaptic plasticity and associative learning and establish LOKI as a powerful approach for isoform-selective kinase interrogation both in vitro and in vivo.

Available for download on Wednesday, April 30, 2031

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