Home Dartmouth Dissertations Page 1

Reference URL

To link to the entire object, paste this link in email, IM or document

To embed the entire object, paste this HTML in website

To link to this page, paste this link in email, IM or document

To embed this page, paste this HTML in website

c-di-GMP mediated regulation of the LapA biofilm adhesin through proteolysis by the calcium-dependent cysteine protease LapG / by Chelsea D. Boyd.

you wish to report:

Your comment:

Your Name:

Submit

Cancel

...

Author	Boyd, Chelsea D.
Title	c-di-GMP mediated regulation of the LapA biofilm adhesin through proteolysis by the calcium-dependent cysteine protease LapG / by Chelsea D. Boyd.
Date	2013
Abstract	The localization of the putative adhesin LapA to the cell surface is a key regulatory step required by Pseudomonas fluorescens Pf0-1 to irreversibly attach to a surface and form a biofilm. LapA contains several domains conserved in predicted bacterial adhesins. The contribution of these domains to biofilm formation and LapA localization to the cell surface was uncertain. Work in our laboratory has shown that the transition from a motile to a biofilm lifestyle is mediated by the intracellular signaling molecule c-di-GMP in response to inorganic phosphate (P[subscript i]). Levels of c-di-GMP are sensed by the inner membrane effector protein LapD. Upon c-di-GMP binding, LapD through an inside-out signaling mechanism activates its periplasmic output to regulate LapA at the cell surface. How regulation was occurring across two membranes was unknown. Therefore, my doctoral research focused on characterizing the determinants in LapA that are required for biofilm formation and localization to the cell surface and determining the mechanism of LapA regulation at the cell surface in conditions unfavorable for biofilm formation. This work characterized LapA as a bona fide cell surface adhesin and determined the significance of predicted domains in relation to LapA localization and function in biofilm formation. Mutagenesis analysis suggests that the N-terminus of LapA is a novel cell surface association domain. The periplasmic cysteine protease, LapG functions to cleave LapA and release the protein from the cell surface in conditions unfavorable for biofilm formation. LapG is a calcium-dependent enzyme. Critical residues and regions of the N-terminus of LapA are required for LapG proteolysis and release of LapA. LapD regulates LapG in a c-di-GMP-dependent manner. Critical residues are required for this interaction disruption to these residues prevents LapD regulation of LapG and unregulated proteolysis of LapA regardless of the P[subscript i] input. We present a model of biofilm formation linking P[subscript i] to the Lap
Description	xiii, 299 leaves : ill. (some col.) 28 cm.
Format	application/pdf
Advisor	George A. O'Toole, Thomas J. Silhavy, Mary Lou Guerinot, Dean R. Madden,
College	Dartmouth Medical School. Department of Microbiology and Immunology.
Issuing Body	Dartmouth Dissertations are made available through the Dartmouth Digital Library.
Degree	Thesis (Ph.D.)--Dartmouth College.
Copyright	All rights reserved. No part of this book may be reproduced in any form by any electronic or mechanical means without permission in writing from the author.
DOI	http://dx.doi.org/10.1349/ddlp.940

Find results with:

Searching collections:

Home Dartmouth Dissertations Page 1

c-di-GMP mediated regulation of the LapA biofilm adhesin through proteolysis by the calcium-dependent cysteine protease LapG / by Chelsea D. Boyd.

Object Description

Description

c-di-GMP mediated regulation of the LapA biofilm adhesin...

c-di-GMP mediated regulation of the LapA biofilm adhesin...

	All
	Pages Enter page numbers or page ranges separated by commas. For example: 1,3,5-12