Date of Award

Spring 5-1-2004

Document Type

Open Access Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

De Camilli, Pietro

Abstract

Tuba is a novel scaffold protein that functions to bring together dynamin with components of the actin cytoskeleton. It is concentrated at synapses in brain and binds dynamin selectively through four N-terminal Src homology-3 (SH3) domains. Tuba binds a variety of actin regulatory proteins, including N-WASP, CR16, WAVE1, WIRE, PIR121, NAP1, and Ena/VASP proteins, via a C-terminal SH3 domain. Direct binding partners include N-WASP and Ena/VASP proteins. Forced targeting of the C-terminal SH3 domain to the mitochondrial surface can promote accumulation of F-actin around mitochondria. A Dbl homology domain present in the middle of Tuba upstream of a Bin/amphiphysin/Rvs (BAR) domain activates Cdc42, but not Rac and Rho, and may thus cooperate with the C terminus of the protein in regulating actin assembly. The BAR domain, a lipid-binding module which also generates curvature in lipid membranes, may functionally replace the pleckstrin homology domain that typically follows a Dbl homology domain. The properties of Tuba provide new evidence for a close functional link between dynamin, Rho GTPase signaling, and the actin cytoskeleton.

Open Access

This Article is Open Access

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