Dataset Information

Molecular mechanisms underlying the BIRC6-mediated regulation of apoptosis and autophagy.

ABSTRACT: Procaspase 9 is the initiator caspase for apoptosis, but how its levels and activities are maintained remains unclear. The gigantic Inhibitor-of-Apoptosis Protein BIRC6/BRUCE/Apollon inhibits both apoptosis and autophagy by promoting ubiquitylation of proapoptotic factors and the key autophagic protein LC3, respectively. Here we show that BIRC6 forms an anti-parallel U-shaped dimer with multiple previously unannotated domains, including a ubiquitin-like domain, and the proapoptotic factor Smac/DIABLO binds BIRC6 in the central cavity. Notably, Smac outcompetes the effector caspase 3 and the pro-apoptotic protease HtrA2, but not procaspase 9, for binding BIRC6 in cells. BIRC6 also binds LC3 through its LC3-interacting region, probably following dimer disruption of this BIRC6 region. Mutation at LC3 ubiquitylation site promotes autophagy and autophagic degradation of BIRC6. Moreover, induction of autophagy promotes autophagic degradation of BIRC6 and caspase 9, but not of other effector caspases. These results are important to understand how the balance between apoptosis and autophagy is regulated under pathophysiological conditions.

SUBMITTER: Liu SS

PROVIDER: S-EPMC10827748 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature

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Molecular mechanisms underlying the BIRC6-mediated regulation of apoptosis and autophagy.

Liu Shuo-Shuo SS Jiang Tian-Xia TX Bu Fan F Zhao Ji-Lan JL Wang Guang-Fei GF Yang Guo-Heng GH Kong Jie-Yan JY Qie Yun-Fan YF Wen Pei P Fan Li-Bin LB Li Ning-Ning NN Gao Ning N Qiu Xiao-Bo XB

Nature communications 20240130 1

Procaspase 9 is the initiator caspase for apoptosis, but how its levels and activities are maintained remains unclear. The gigantic Inhibitor-of-Apoptosis Protein BIRC6/BRUCE/Apollon inhibits both apoptosis and autophagy by promoting ubiquitylation of proapoptotic factors and the key autophagic protein LC3, respectively. Here we show that BIRC6 forms an anti-parallel U-shaped dimer with multiple previously unannotated domains, including a ubiquitin-like domain, and the proapoptotic factor Smac/D ...[more]

PMID: 38291026

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Project description:Nuclear factor‑κB (NF‑κB) is widely involved in various lymphoid malignancies. However, its exact functional role and potential regulatory mechanisms in Hodgkin's lymphoma (HL) remains unclear. The present study aimed to investigate the regulatory mechanism of NF‑κB in HL by analysis of a gene expression profile that was obtained from HL cells with or without NF‑κB subunit 2 (NFKB2) knockdown. The GSE64234 dataset containing 6 HL cell line specimens transfected with small interfering (si)RNA against NFKB2 and 6 control specimens transfected with non‑targeting siRNA sequences was downloaded from the Gene Expression Omnibus database. Based on these data, differentially expressed genes (DEGs) were screened for following data preprocessing. Functional enrichment analysis was subsequently conducted among the identified upregulated and downregulated DEGs. Additionally, a protein‑protein interaction (PPI) network was constructed and module analyses were performed. Finally, microRNAs (miRNAs/miRs) targeting the identified DEGs were predicted for the construction of a miRNA‑target regulatory network. A total of 253 DEGs were identified, consisting of 109 upregulated and 144 downregulated DEGs. Pathway enrichment analysis revealed that B‑cell lymphoma 2‑like 1 (BCL2L1) was significantly enriched in the NF‑κB signaling pathway, and colony‑stimulating factor 2 (CSF2) and BCL2L1 were enriched in the Jak‑signal transducer and activator of transcription (STAT) signaling pathway. BCL2L1 and CSF2 were determined to be hub genes in the PPI network. A total of 6 miRNAs, including let‑7a‑5p, miR‑9‑5p, miR‑155‑5p, miR‑135a‑5p, miR‑17‑5p and miR‑375, were identified in the miRNA‑target regulatory network. The results of the present study indicated that NFKB2 may be involved in HL development through regulation of BCL2L1, CSF2, miR‑135a‑5p, miR‑155‑5p and miR‑9‑5p expression, as well as the modulation of Jak‑STAT and NF‑κB signaling pathways.

Dataset Information

Molecular mechanisms underlying the BIRC6-mediated regulation of apoptosis and autophagy.

Publications

Molecular mechanisms underlying the BIRC6-mediated regulation of apoptosis and autophagy.

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