ANKRD11

ANKRD11 Full Name

ankyrin repeat domain 11

ANKRD11 Introduction

ANKRD11 (also known as ankyrin repeat domain-containing protein 11, ANCO-1, or ankyrin repeat-containing cofactor 1) is a large multidomain protein that functions as a transcriptional co-regulator, interacting with both histone deacetylases (HDACs) and various transcription factors to modulate gene expression. ANKRD11 was originally identified as a p160 co-activator-binding protein and a component of the NCoR (nuclear receptor corepressor) complex, linking it to the regulation of nuclear receptor signaling, cell cycle progression, and development. The gene is ubiquitously expressed, with particularly high levels in the brain, where it plays essential roles in neuronal development and synaptic function. Haploinsufficiency of ANKRD11 causes KBG syndrome, a rare neurodevelopmental disorder characterized by intellectual disability, macrodontia (large teeth), short stature, and distinct facial features. Beyond its role in development, ANKRD11 has been implicated as a tumor suppressor in various cancers, with frequent loss-of-function mutations identified in prostate cancer, breast cancer, ovarian cancer, and hematologic malignancies. The diverse functions of ANKRD11 in transcriptional regulation, chromatin remodeling, and DNA damage response make it a critical regulator of both normal development and disease pathogenesis.

Figure 1. Schematic structure of ANKRD11.

Biological Functions in Transcriptional Regulation and Neurodevelopment
ANKRD11 functions as a transcriptional co-regulator that can both activate and repress gene expression depending on the cellular context and interacting partners. As a component of the NCoR (nuclear receptor corepressor) complex, ANKRD11 mediates transcriptional repression by recruiting HDAC3 to specific genomic loci, leading to histone deacetylation and chromatin compaction. This repression mechanism is critical for the regulation of genes involved in cell cycle progression, differentiation, and development. Conversely, ANKRD11 can also function as a transcriptional co-activator by binding to p160 co-activators and facilitating the recruitment of histone acetyltransferases (HATs) such as p300 and CBP. This dual function allows ANKRD11 to fine-tune gene expression in response to various signals. In neurodevelopment, ANKRD11 plays essential roles in neuronal differentiation, dendritic morphogenesis, and synaptic plasticity. ANKRD11 regulates the expression of genes involved in axon guidance, synapse formation, and neurotransmission, including BDNF, RELN, and GRIN2B. Haploinsufficiency of ANKRD11 causes KBG syndrome, an autosomal dominant neurodevelopmental disorder characterized by mild to moderate intellectual disability, global developmental delay, behavioral abnormalities (including autism spectrum disorder traits and attention-deficit/hyperactivity disorder), distinctive facial features (triangular face, prominent nasal bridge, synophrys), macrodontia of the upper central incisors, short stature, and skeletal anomalies. Brain imaging may show corpus callosum abnormalities, enlarged ventricles, or cerebellar hypoplasia. The severity of KBG syndrome is variable, even among individuals with the same ANKRD11 mutation, suggesting the influence of modifier genes and environmental factors.

Role as a Tumor Suppressor in Cancer
ANKRD11 is increasingly recognized as a tumor suppressor gene that is frequently inactivated in various human malignancies. Loss-of-function mutations in ANKRD11 have been identified in prostate cancer (particularly in metastatic castration-resistant prostate cancer), breast cancer, ovarian cancer, endometrial cancer, pancreatic cancer, and hematologic malignancies including chronic lymphocytic leukemia (CLL) and multiple myeloma. The mutation spectrum includes nonsense, frameshift, splice-site, and missense mutations, as well as large deletions, all consistent with loss-of-function mechanisms. ANKRD11 suppresses tumorigenesis through multiple mechanisms. First, ANKRD11 physically interacts with and stabilizes the tumor suppressor p53, enhancing p53-mediated transcriptional activation of pro-apoptotic genes such as PUMA, BAX, and p21. Loss of ANKRD11 leads to reduced p53 activity, allowing cells with DNA damage to evade apoptosis and continue proliferating. Second, ANKRD11 negatively regulates the PI3K/AKT signaling pathway, a key driver of cell survival and growth. ANKRD11 binds to and promotes the degradation of AKT1, reducing its kinase activity and downstream signaling. Third, ANKRD11 represses the expression of oncogenes including MYC, CCND1 (cyclin D1), and MMP-9 through recruitment of HDAC3 to their promoters. Fourth, ANKRD11 participates in the DNA damage response by promoting the deacetylation of p53 and other repair factors, facilitating proper repair of double-strand breaks. Consequently, ANKRD11 loss leads to genomic instability, increased mutation accumulation, and accelerated tumor progression. Clinically, reduced ANKRD11 expression correlates with advanced tumor stage, increased metastasis, poor patient survival, and resistance to chemotherapy and targeted therapies.

Alternate Names for ANKRD11

ANKRD11; ankyrin repeat domain 11; ankyrin repeat domain-containing protein 11; LZ16; T13; ANCO 1; ANCO1; Ankyrin repeat containing cofactor 1; Ankyrin repeat domain 11; Ankyrin repeat domain containing protein 11; LZ16; T13; ankyrin repeat-containing cof