Dataset Information

Protein-protein interactions between jasmonate-related master regulator MYC and transcriptional mediator MED25 depend on a short binding domain.

ABSTRACT: A network of protein-protein interactions (PPI) is involved in the activation of (+)-7-iso-jasmonoyl-L-isoleucine (JA-Ile), a plant hormone that regulates plant defense responses as well as plant growth and development. In the absence of JA-Ile, inhibitory protein jasmonate-ZIM-domain (JAZ) represses JA-related transcription factors, including a master regulator, MYC. In contrast, when JA-Ile accumulates in response to environmental stresses, PPI occurs between JAZ and the F-box protein COI1, which triggers JAZ degradation, resulting in derepressed MYC that can interact with the transcriptional mediator MED25 and upregulate JA-Ile-related gene expression. Activated JA signaling is eventually suppressed through the catabolism of JA-Ile and feedback suppression by JAZ splice variants containing a cryptic MYC-interacting domain (CMID). However, the detailed structural basis of some PPIs involved in JA-Ile signaling remains unclear. Herein, we analyzed PPI between MYC3 and MED25, focusing on the key interactions that activate the JA-Ile signaling pathway. Biochemical assays revealed that a short binding domain of MED25 (CMIDM) is responsible for the interaction with MYC, and that a bipartite interaction is critical for the formation of a stable complex. We also show the mode of interaction between MED25 and MYC is closely related to that of CMID and MYC. In addition, quantitative analyses on the binding of MYC3-JAZs and MYC3-MED25 revealed the order of binding affinity as JAZ^Jas < MED25^CMIDM < JAZ^CMID, suggesting a mechanism for how the transcriptional machinery causes activation and negative feedback regulation during jasmonate signaling. These results further illuminate the transcriptional machinery responsible for JA-Ile signaling.

SUBMITTER: Takaoka Y

PROVIDER: S-EPMC8752898 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Human respiratory syncytial virus (RSV) is the leading cause of severe acute lower respiratory tract infections in infants worldwide. Nonstructural protein NS1 of RSV modulates the host innate immune response by acting as an antagonist of type I and type III interferon (IFN) production and signaling in multiple ways. Likely, NS1 performs this function by interacting with different host proteins. In order to obtain a comprehensive overview of the NS1 interaction partners, we performed three complementary protein-protein interaction screens, i.e., BioID, MAPPIT, and KISS. To closely mimic a natural infection, the BioID proximity screen was performed using a recombinant RSV in which the NS1 protein is fused to a biotin ligase. Remarkably, MED25, a subunit of the Mediator complex, was identified in all three performed screening methods as a potential NS1-interacting protein. We confirmed the interaction between MED25 and RSV NS1 by coimmunoprecipitation, not only upon overexpression of NS1 but also with endogenous NS1 during RSV infection. We also demonstrate that the replication of RSV can be enhanced in MED25 knockout A549 cells, suggesting a potential antiviral role of MED25 during RSV infection. Mediator subunits function as transcriptional coactivators and are involved in transcriptional regulation of their target genes. Therefore, the interaction between RSV NS1 and cellular MED25 might be beneficial for RSV during infection by affecting host transcription and the host immune response to infection. IMPORTANCE Innate immune responses, including the production of type I and III interferons, play a crucial role in the first line of defense against RSV infection. However, only a poor induction of type I IFNs is observed during RSV infection, suggesting that RSV has evolved mechanisms to prevent type I IFN expression by the infected host cell. A unique RSV protein, NS1, is largely responsible for this effect, probably through interaction with multiple host proteins. A better understanding of the interactions that occur between RSV NS1 and host proteins may help to identify targets for an effective antiviral therapy. We addressed this question by performing three complementary protein-protein interaction screens and identified MED25 as an RSV NS1-interacting protein. We propose a role in innate anti-RSV defense for this Mediator complex subunit.

Dataset Information

Protein-protein interactions between jasmonate-related master regulator MYC and transcriptional mediator MED25 depend on a short binding domain.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets