title: Identification of DNAJA1 as a novel interacting partner and a substrate of human transglutaminase 2.
abstract: Transglutaminase 2 (TG2) is a ubiquitously expressed multifunctional member of the transglutaminase enzyme family. It has been implicated to have roles in many physiological and pathological processes such as differentiation, apoptosis, signal transduction, adhesion and migration, wound healing and inflammation. Previous studies revealed that TG2 has various intra- and extra-cellular interacting partners, which contribute to these processes. In the present study, we identified a molecular co-chaperone, DNAJA1, as a novel interacting partner of human TG2 using a GST pull-down assay and subsequent mass spectrometry analysis, and further confirmed this interaction via ELISA and surface plasmon resonance measurements. Interaction studies were also performed with domain variants of TG2 and results suggest that the catalytic core domain of TG2 is essential for the TG2-DNAJA1 interaction. Cross-linking activity was not essential for the interaction since DNAJA1 was also found to interact with the catalytically inactive form of TG2. Furthermore, we have showed that DNAJA1 interacts with the open form of TG2 and regulates its transamidation activity under both in vitro and in situ conditions. We also found that DNAJA1 is a glutamine donor substrate of TG2. Since DNAJA1 and TG2 are reported to regulate common pathological conditions such as neurodegenerative disorders and cancer, the findings in the present paper open up possibilities to explore molecular mechanisms behind TG2-regulated functions.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary UD-GenoMed Medical Genome Technologies, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary.
authors.forename: Elvan
authors.initials: E
authors.lastname: Ergülen
authors.affiliation: Department of Medical Chemistry, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary.
authors.forename: Bálint
authors.initials: B
authors.lastname: Bécsi
authors.affiliation: Department of Biophysics, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary.
authors.forename: István
authors.initials: I
authors.lastname: Csomós
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary MTA-DE Stem Cell, Apoptosis and Genomics Research Group of Hungarian Academy of Sciences, Debrecen, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Fésüs
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Debrecen, Nagyerdei krt 98, Debrecen H-4032, Hungary Jawaharlal Nehru University, New Delhi 67, India.
authors.forename: Kajal
authors.initials: K
authors.lastname: Kanchan
mesh_terms: D000588:Amines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism; D057809:HEK293 Cells; D050956:HSP40 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D011485:Protein Binding; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D055550:Protein Stability; D020349:Surface Plasmon Resonance; D053719:Tandem Mass Spectrometry; D011503:Transglutaminases / Q000378:metabolism*
chemical_list: D000588:Amines; C107481:DNAJA1 protein, human; D050956:HSP40 Heat-Shock Proteins; D005973:Glutamine; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins
keywords: DNAJA1/HSP40; core domain; in situ cross-linking activity; protein–protein interaction; transamidation; transglutaminase 2