Date of Award

Summer 2023

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Microbiology, Molecular Biology and Biochemistry

Abstract

In confined spaces, migrating cells can undergo mesenchymal-to-amoeboid transitions by altering their cortical dynamics and adhesion with the environment. Septins frequently associate with cortical actin and non-muscle myosin (NMII), but the functional nature of these interactions remains unclear. Upon non-adhesive confinement and NMII enrichment, fibroblasts can switch to a fast, leader bleb-based mode of motility, characterized by the absence of adhesions and stress fibers and formation of a single, elongated leader bleb. During this transition, cortical actin remodeling and polarized NMII contractility drive leader bleb stabilization by generating long-range cortical flows, in coordination with changes in septin localization and assembly dynamics. Meanwhile, septin depletion increases global NMII expression, promoting cellular rounding and transient blebbing under non-adhesive confinement. These findings demonstrate the plasticity of fibroblast migration behavior, mediated by cortical septin-actomyosin remodeling and, further, open the door for future studies on the functional relationship between septins and NMII at the cortex.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

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