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Dr. Velia Fowler, PhD

University of Delaware

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University of Delaware

Bio

Dr. Velia M. Fowler is a Professor and Chair in the Department of Biological Sciences at the University of Delaware in Newark, DE. She leads an interdisciplinary team to study the regulation of actin filament dynamics in lenses, red blood cells and striated muscles. Actin filaments are intrinsically polarized, with distinct fast growing (barbed) and slow growing (pointed) ends. Dr. Fowler discovered a novel family of actin filament pointed-end capping proteins, known as tropomodulins (Tmods), that are present in all cells. Tmods are the only proteins that regulate pointed-end actin filament dynamics and are critical for assembly and architecture of both stable and dynamic cell cytoskeletons.

In the lens, the lab aims to understand how diverse actin filament networks regulated by Tmods and their binding partners, tropomyosins, affect the morphological integrity, biomechanics and transparency of the lens. Through integration of cell biology, biochemistry, high resolution microscopy and mouse genetics, the Fowler lab demonstrated that loss of Tmod1 in mouse lenses leads to abnormal shapes of mature fiber cells and loss of lens stiffness due to dissociation of Tpm3.5 and spectrin from fiber cell membranes.  On the other hand, loss of the Tmod1-binding partner tropomyosin (Tpm3.5), leads to loss of lens stiffness due to conversion of Tpm 3.5, Tmod1 and fimbrin cross-linked stiff actin networks to softer networks cross-linked by alpha-actinin and spectrin.  Current research is aimed at defining the compositions of the diverse actin filament networks in epithelial cells as compared to those in fiber cells, and their contributions to lens cell microstructure and age-dependent anterior subcapsular cataracts and lens stiffening during aging.

Regulation of the assembly and disassembly of actin filaments by Tmods and tropomyosins is crucial for embryonic development and maintaining life-long homeostasis in adult tissues. With over 100 publications, the lab continues to research the connections between actin dynamics, assembly and organization of actin cytoskeletal structures, cell shape and integrity, and physiological function and disease.