Atxn1
Developmental stage
Transient expression burst in Purkinje cells as the cerebellar cortex becomes functional (postnatal day 14), and in mesenchymal cells of the developing intervertebral disks of the spinal column.
Domain
The AXH domain is required for interaction with CIC.
Function
Chromatin-binding factor that repress Notch signaling in the absence of Notch intracellular domain by acting as a CBF1 corepressor. Binds to the HEY promoter and might assist, along with NCOR2, RBPJ-mediated repression (By similarity). May be involved in RNA metabolism (By similarity). In concert with CIC and ATXN1L, involved in brain development (PubMed:28288114).
Post-translational modifications
Ubiquitinated by UBE3A, leading to its degradation by the proteasome. The presence of poly-Gln repeats in trangenic models developed to replicate phenotypes of the spinocerebellar ataxia 1 disease (SCA1) impair ubiquitination and degradation, leading to accumulation of Atxn1 in neurons and subsequent toxicity.
Sumoylation is dependent on nuclear localization and phosphorylation at Ser-751.
Sequence Similarities
Belongs to the ATXN1 family.
Tissue Specificity
Expressed in the cortex and hypothalamus (at protein level). Widely expressed. In brain, the pattern of distribution is limited to neuron populations.
Cellular localization
- Cytoplasm
- Nucleus
- Colocalizes with USP7 in the nucleus.
Alternative names
Sca1, Atxn1, Ataxin-1, Spinocerebellar ataxia type 1 protein homolog