{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/297969"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/297969","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"An investigation of the interaction between the immune system GTPase GIMAP6 and an autophagy gene 8 homologue GABARAPL2","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 protein unable to interact with GIMAP6, was replaced by GABARAPL2’s N-terminal α-helix reproduced the interaction suggesting that this region is critical for the interaction. Studies in our group have shown that GIMAP6 relocalises to autophagosomes on induction of autophagy. I have shown that variants of GIMAP6 unable to interact with GABARAPL2 fail to display a similar relocalisation. Finally, recent research has demonstrated that members of the GIMAP family can homo- and hetero-dimerise. I have shown that GIMAP6 can interact with itself and intriguingly, also shows a specific interaction with GIMAP7. Contrary to what was observed for the GIMAP6-GABARAPL2 interaction, truncating the N-terminus of GIMAP6 abrogated the interaction with GIMAP7. These findings evoke the possibility that the GIMAP GTPases function together in an interacting network.","abstract_html":"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 protein unable to interact with GIMAP6, was replaced by GABARAPL2’s N-terminal α-helix reproduced the interaction suggesting that this region is critical for the interaction. Studies in our group have shown that GIMAP6 relocalises to autophagosomes on induction of autophagy. I have shown that variants of GIMAP6 unable to interact with GABARAPL2 fail to display a similar relocalisation. Finally, recent research has demonstrated that members of the GIMAP family can homo- and hetero-dimerise. I have shown that GIMAP6 can interact with itself and intriguingly, also shows a specific interaction with GIMAP7. Contrary to what was observed for the GIMAP6-GABARAPL2 interaction, truncating the N-terminus of GIMAP6 abrogated the interaction with GIMAP7. These findings evoke the possibility that the GIMAP GTPases function together in an interacting network.","abstract_has_math":false,"creators":["Mukadam, Aamir"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Butcher, Geoff"],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-07-22","date_published":"2014-07-22","updated_at":"2026-07-22T22:24:28Z","subjects":["GTPases","GIMAPs","autophagy"],"languages":["en"],"rights":[],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d51dc030-4e0e-41ec-9e5f-7657c05a5050/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.45023","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Butcher, Geoff"]},{"key":"dc:creator","label":"Author","values":["Mukadam, Aamir"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2014-07-22"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/297969"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["GTPases","GIMAPs","autophagy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d51dc030-4e0e-41ec-9e5f-7657c05a5050/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.45023"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d2caa1c7-cd1c-4789-82b3-c4fc4e2bc678/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["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 protein unable to interact with GIMAP6, was replaced by GABARAPL2’s N-terminal α-helix reproduced the interaction suggesting that this region is critical for the interaction. Studies in our group have shown that GIMAP6 relocalises to autophagosomes on induction of autophagy. I have shown that variants of GIMAP6 unable to interact with GABARAPL2 fail to display a similar relocalisation. Finally, recent research has demonstrated that members of the GIMAP family can homo- and hetero-dimerise. I have shown that GIMAP6 can interact with itself and intriguingly, also shows a specific interaction with GIMAP7. Contrary to what was observed for the GIMAP6-GABARAPL2 interaction, truncating the N-terminus of GIMAP6 abrogated the interaction with GIMAP7. These findings evoke the possibility that the GIMAP GTPases function together in an interacting network."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["87eda9de84448d1f82354d60eee3eb5f","a1d8146ed3966fdd7cc1e2f6525b0d73"]},{"key":"dc:title","label":"Title","values":["An investigation of the interaction between the immune system GTPase GIMAP6 and an autophagy gene 8 homologue GABARAPL2"]}]}],"canonical_facts":{"dc:contributor.advisor":["Butcher, Geoff"],"dc:creator":["Mukadam, Aamir"],"dc:date.issued":["2014-07-22"],"dc:description.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 protein unable to interact with GIMAP6, was replaced by GABARAPL2’s N-terminal α-helix reproduced the interaction suggesting that this region is critical for the interaction. Studies in our group have shown that GIMAP6 relocalises to autophagosomes on induction of autophagy. I have shown that variants of GIMAP6 unable to interact with GABARAPL2 fail to display a similar relocalisation. Finally, recent research has demonstrated that members of the GIMAP family can homo- and hetero-dimerise. I have shown that GIMAP6 can interact with itself and intriguingly, also shows a specific interaction with GIMAP7. Contrary to what was observed for the GIMAP6-GABARAPL2 interaction, truncating the N-terminus of GIMAP6 abrogated the interaction with GIMAP7. These findings evoke the possibility that the GIMAP GTPases function together in an interacting network."],"dc:format.checksum.md5":["87eda9de84448d1f82354d60eee3eb5f","a1d8146ed3966fdd7cc1e2f6525b0d73"],"dc:identifier.doi":["10.17863/CAM.45023"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d2caa1c7-cd1c-4789-82b3-c4fc4e2bc678/download"],"dc:language":["en"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/297969"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/d51dc030-4e0e-41ec-9e5f-7657c05a5050/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["GTPases","GIMAPs","autophagy"],"dc:title":["An investigation of the interaction between the immune system GTPase GIMAP6 and an autophagy gene 8 homologue GABARAPL2"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:28Z"}