E2F8

E2F8 Full Name

E2F transcription factor 8

E2F8 Introduction

E2F8, officially named E2F transcription factor 8, is a protein-coding gene located at human chromosome 11p15.1 with the official HGNC identifier 24727 and gene ID 79733. Its primary alternate symbol is FLJ23311, and it is also commonly abbreviated as E2F-8 in academic research. As a validated eukaryotic gene, it belongs to the extended E2F transcription factor family and is uniquely categorized as an atypical E2F member distinct from canonical E2F subtypes. Unlike early-discovered E2F1–E2F7, E2F8 was identified in the mid-2000s as a novel cell cycle-related transcription regulator, filling the research gap of atypical repressive E2F factors in human cell cycle signaling networks. Multiple alternatively spliced transcript variants of E2F8 have been verified, yet all encoded isoforms maintain consistent core protein functions.E2F8 possesses a distinctive protein structure that differentiates it from typical E2F family members, endowing it with independent transcriptional regulatory capabilities. The most prominent structural feature is its possession of two tandem and functional DNA-binding domains, which enable stable binding to E2F-responsive promoter sequences without relying on auxiliary proteins. Structurally, E2F8 lacks both the DP-dimerization domain and retinoblastoma (RB)-binding region that are indispensable for the activity of canonical E2F activators and traditional repressors. Crystallographic data (PDB ID: 4YO2) further confirms its atypical spatial conformation, with a 3.07 Å resolution structure revealing unique folding patterns that support its standalone DNA binding. This structural specificity allows E2F8 to function independently in transcriptional regulation, rather than forming heterodimers with DP proteins as required by other E2F members.

Figure1. Structure of E2F8.(Morgunova E, Yin Y, Jolma A, et al. 2015)

Molecular Regulatory Mechanisms of E2F8
E2F8 expression and activity are tightly regulated by cell cycle-dependent post-translational modifications and ubiquitin-mediated degradation pathways to ensure ordered cell cycle progression. During the mitosis-to-G1 phase transition, the E3 ubiquitin ligase Anaphase-Promoting Complex/Cyclosome (APC/C) serves as a core regulatory hub to mediate E2F8 degradation. The phosphorylation status of E2F8, dynamically controlled by Cdk1 kinase and PP2A phosphatase, acts as a molecular switch that determines its stability and subcellular localization. Hyperphosphorylated E2F8 tends to be recognized and ubiquitinated by APC/C for subsequent proteasomal degradation in late mitosis, while dephosphorylated E2F8 accumulates in the G1 phase to exert transcriptional repression. This reversible post-translational regulatory cycle ensures that E2F8 exerts stage-specific inhibitory effects on cell cycle gene expression, avoiding continuous proliferation arrest and guaranteeing the orderly progression of cell division.

Disease Association and Clinical Research Significance
Aberrant E2F8 expression is closely correlated with the occurrence and progression of multiple human diseases, including malignant tumors and neurodegenerative disorders. In oncology research, E2F8 exhibits subtype-specific oncogenic roles; its upregulation significantly promotes the proliferation and invasion of basal-like breast cancer cells, making it a promising therapeutic target for this aggressive breast cancer subtype. Conversely, abnormal E2F8 overexpression is also involved in the pathogenesis of Alzheimer's disease, where it suppresses the transcription of MMP9 and BCL2 genes, triggering amyloid-beta accumulation and neuronal apoptosis to exacerbate cognitive impairment. Emerging studies further indicate that E2F8 dysregulation is linked to abnormal cell proliferation in other solid tumors and tissue developmental disorders, demonstrating its dual regulatory roles in maintaining physiological homeostasis and driving pathological progression. Targeting E2F8-mediated transcriptional networks has thus become a novel direction for precision disease intervention and clinical biomarker development.

Alternate Names for E2F8

E2F8; E2F transcription factor 8; transcription factor E2F8; FLJ23311; E2F family member 8; E2F-8;

• 1.Morgunova E, Yin Y, Jolma A, et al. Structural insights into the DNA-binding specificity of E2F family transcription factors. Nature communications, 2015, 6(1): 10050.