UROP Project

Characterizing Neurodevelopmental Disease-Associated Conformational Changes in the βII-Spectrin Actin-Binding Domain

Neurodevelopmental Disorders, Biological Sciences, Biochemistry, Structural Biology, Protein Chemistry, Recombinant Proteins, Cytoskeletal Proteins, Spectrin, SPTBN1, Actin-Binding Proteins, Protein-Protein Interactions

Research Mentor: Dr. Helene Tigro, She/Her
Department, College, Affiliation: Florida State University, Education, Health, and Human Sciences
Contact Email: ht24@fsu.edu
Research Assistant Supervisor (if different from mentor): Dr. Christopher Solis He/His
Research Assistant Supervisor Email: csolis@fsu.edu
Faculty Collaborators:
Faculty Collaborators Email:

Looking for Research Assistants: Yes
Number of Research Assistants: 1
Relevant Majors: Biochemistry, Neuroscience, Chemistry, Biology, Computational Biology, Engineering
Project Location: On FSU Main Campus
Research Assistant Transportation Required:
Remote or In-person: In-person
Approximate Weekly Hours: 10 hours, During business hours
Roundtable Times and Zoom Link:

• Day: Wednesday, September 2
  Start Time: 1:00
  End Time: 2:30
  Zoom Link: https://fsu.zoom.us/j/98918911622

Project Description

βII-spectrin (SPTBN1) is a cytoskeletal scaffolding protein that links F-actin to membrane-associated protein complexes and plays essential roles in neuronal development, membrane organization, and maintenance of cellular architecture. Its N-terminal actin-binding domain (ABD) contains tandem calponin homology domains (CH1 and CH2) that regulate actin interactions through a dynamic equilibrium between closed (autoinhibited) and open conformations. Disease-associated variants within the ABD disrupt this regulatory mechanism and have been linked to neurodevelopmental disorders characterized by developmental delay, intellectual disability, and behavioral abnormalities.
Several pathogenic variants are predicted to alter interactions at the CH1-CH2 interface, thereby shifting the structural equilibrium of the ABD. Some mutations may stabilize the closed state and reduce actin association, whereas others are predicted to promote domain opening and enhance actin affinity. This project will experimentally and computationally characterize recombinant human βII-spectrin wild-type (WT) and mutant ABD proteins to determine how disease-associated mutations affect protein structure and function.
Despite the growing number of SPTBN1 variants identified in patients, the molecular mechanisms underlying their pathogenicity remain poorly understood. Because βII-spectrin is critical for axonal growth, neuronal connectivity, and organization of the neuronal cytoskeleton, disruption of its actin-binding properties may contribute directly to disease development. By linking patient-associated mutations to structural and functional consequences at the molecular level, this project aims to advance our understanding of SPTBN1-associated neurodevelopmental disorders and the mechanisms that drive neuronal dysfunction.

Research Tasks: The student will conduct a literature review on spectrin biology, actin-binding proteins, and connection to neurodevelopmental disorders. Research activities will include recombinant expression and purification of wild-type and disease-associated βII-spectrin actin-binding domain (ABD) variants, followed by protein characterization using SDS-PAGE, native PAGE, and mass photometry. The effects of mutations on F-actin binding will be quantified through actin co-sedimentation assays. Computational analyses will include AlphaFold modeling, ChimeraX visualization, structural measurements, and electrostatic surface analysis. Experimental and computational results will be integrated to determine how pathogenic SPTBN1 variants alter βII-spectrin structure and function. Statistical analysis, data interpretation, and figure preparation will also be performed.

Skills that research assistant(s) may need: Good theoretical understanding of biology and chemistry. Interest in protein biochemistry, structural biology, and molecular mechanisms of disease. Experience with laboratory techniques is helpful but not required. Experience with molecular visualization software (ChimeraX, PyMOL), programming (Python, R, MATLAB), or structural biology tools is beneficial but not required. Strong organizational, time-management, and communication skills, along with the ability to work independently and as part of a team, are highly valued.