An investigation of the interaction between the immune system GTPase GIMAP6 and an autophagy gene 8 homologue GABARAPL2
type: CreativeWork
description: The GTPase of immunity-associated proteins (GIMAP) is expressed in eukaryotic phyla including a subset of molluscs, vertebrates, and some protists. It is predominantly ex- pressed in the lymphoid organs of mammals and other vertebrates where it plays roles in the homeostasis of the immune system. My study focuses on human (h) GIMAP6, a cytosolic member of the GIMAP family that is widely expressed across the lymphoid lineages. Studies within our group have uncovered a highly specific interaction between GIMAP6 and hGABARAPL2 (gamma- aminobutyric acid receptor-associated protein-like 2), a mammalian homologue of the autophagy-related protein 8 (Atg8). Using bacterially expressed GABARAPL2 and GIMA- P6 I have shown that the interaction between the two proteins is direct. My studies have attempted to gain an understanding of the molecular requirements for this interaction using site-directed mutagenesis and pull-down assays. Mutational analyses, including point mutations within, and truncations of, GIMAP6 and GABARAPL2 have revealed a number of things. Close to its N-terminus GIMAP6 carries a sequence correspond- ing to a canonical Atg8 interacting motif (AIM), a motif frequently found in proteins that interact with the Atg8 family. My studies indicate, however, that these residues do not play a role in the interaction. Using GTP-agarose, I was able to demonstrate that GIMAP6 could bind GDP and GTP and by mutating key residues within its GTP bind- ing domain, I could disrupt the interaction of GIMAP6 with GABARAPL2. I have also shown that the C-terminal 10 amino acids of GIMAP6 are necessary for the interaction. Interestingly, variants of GIMAP6 that were unable to bind GTP-agarose were also un- able to interact with GABARAPL2, hinting at a crucial role for nucleotide binding in the GIMAP6-GABARAPL2 interaction. Within GABARAPL2, deletion of the N-terminal α-helix resulted in loss of the interaction. A chimeric protein in which the correspond- ing region in MAP1LC3B, a …
abstract: The GTPase of immunity-associated proteins (GIMAP) is expressed in eukaryotic phyla including a subset of molluscs, vertebrates, and some protists. It is predominantly ex- pressed in the lymphoid organs of mammals and other vertebrates where it plays roles in the homeostasis of the immune system. My study focuses on human (h) GIMAP6, a cytosolic member of the GIMAP family that is widely expressed across the lymphoid lineages. Studies within our group have uncovered a highly specific interaction between GIMAP6 and hGABARAPL2 (gamma- aminobutyric acid receptor-associated protein-like 2), a mammalian homologue of the autophagy-related protein 8 (Atg8). Using bacterially expressed GABARAPL2 and GIMA- P6 I have shown that the interaction between the two proteins is direct. My studies have attempted to gain an understanding of the molecular requirements for this interaction using site-directed mutagenesis and pull-down assays. Mutational analyses, including point mutations within, and truncations of, GIMAP6 and GABARAPL2 have revealed a number of things. Close to its N-terminus GIMAP6 carries a sequence correspond- ing to a canonical Atg8 interacting motif (AIM), a motif frequently found in proteins that interact with the Atg8 family. My studies indicate, however, that these residues do not play a role in the interaction. Using GTP-agarose, I was able to demonstrate that GIMAP6 could bind GDP and GTP and by mutating key residues within its GTP bind- ing domain, I could disrupt the interaction of GIMAP6 with GABARAPL2. I have also shown that the C-terminal 10 amino acids of GIMAP6 are necessary for the interaction. Interestingly, variants of GIMAP6 that were unable to bind GTP-agarose were also un- able to interact with GABARAPL2, hinting at a crucial role for nucleotide binding in the GIMAP6-GABARAPL2 interaction. Within GABARAPL2, deletion of the N-terminal α-helix resulted in loss of the interaction. A chimeric protein in which the correspond- ing region in MAP1LC3B, a …
author: Mukadam, Aamir
language: en
keywords: GTPases, GIMAPs, autophagy
license: https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d51dc030-4e0e-41ec-9e5f-7657c05a5050/download
license: https://www.rioxx.net/licenses/all-rights-reserved/
date published: 2014-07-22
date modified: 2026-07-22T22:24:28Z
provider: Cambridge University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Cambridge

PropertyValue
property ID: DOI
value: 10.17863/CAM.45023