Date of Award

2021

Document Type

Dissertation

Degree Name

Ph.D.

Organizational Unit

College of Natural Science and Mathematics, Biological Sciences

First Advisor

Erich J. Kushner

Second Advisor

Yan Qin

Third Advisor

Bruce Appel

Fourth Advisor

Michelle Knowles

Keywords

Collagen IV, Endothelial, Lysyl hydroxylase 3, Rab10, Rab25, Vasculature

Abstract

Collagen type IV (Col IV) is a basement membrane protein associated with early blood vessel morphogenesis and is essential for blood vessel stability. Defects in vascular Col IV deposition are the basis of heritable disorders, such as small vessel disease, marked by cerebral hemorrhage and drastically shorten lifespan. To date, little is known about how endothelial cells regulate the intracellular transport and selective secretion of Col IV in response to angiogenic cues, leaving a void in our understanding of this process. Our aim was to identify trafficking pathways that regulate Col IV deposition during angiogenic blood vessel development. We have identified the GTPase Rab10 as a major regulator of Col IV vesicular trafficking during vascular development using both in vitro imaging and biochemistry as well as in vivo models. Knockdown of Rab10 reduced de novo Col IV secretion in vitro and in vivo. Mechanistically, we determined that Rab10 is an indirect mediator of Col IV secretion partnering with atypical Rab25 to deliver the enzyme lysyl hydroxylase 3 (LH3) to Col IV-containing vesicles staged for secretion. Loss of Rab10 or Rab25 results in depletion of LH3 from Col IV-containing vesicles and rapid lysosomal degradation of Col IV. Furthermore, we demonstrate that Rab10 is Notch responsive, indicating a novel connection between permissive Notch-based blood vessel maturation programs and vesicle trafficking. Our results illustrate both a new trafficking-based component in the regulated secretion of Col IV and how this vesicle trafficking program interfaces with Notch signaling to fine-tune basement membrane secretion during blood vessel development.

Publication Statement

Copyright is held by the author. User is responsible for all copyright compliance.

Rights Holder

Stephen J.B. Gross

Provenance

Received from ProQuest

File Format

application/pdf

Language

en

File Size

116 pgs

Discipline

Molecular biology

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