NACA
Domain
The positively charged inner surface of the NAC-A/B domain is crucial for NACA localization in the nucleus and DNA-binding. This region is blocked from binding nucleic acids in the heterodimeric complex by a helix region in the beta-subunit, it also displays much higher affinity for RNA than DNA.
Function
Prevents inappropriate targeting of non-secretory polypeptides to the endoplasmic reticulum (ER). Binds to nascent polypeptide chains as they emerge from the ribosome and blocks their interaction with the signal recognition particle (SRP), which normally targets nascent secretory peptides to the ER. Also reduces the inherent affinity of ribosomes for protein translocation sites in the ER membrane (M sites). May act as a specific coactivator for JUN, binding to DNA and stabilizing the interaction of JUN homodimers with target gene promoters.
Post-translational modifications
Phosphorylation of Thr-159 by GSK3B may promote proteasome mediated degradation (By similarity). Phosphorylation of Ser-43 by ILK during cell adhesion may promote nuclear localization.
Sequence Similarities
Belongs to the NAC-alpha family.
Tissue Specificity
Ubiquitously expressed.
Cellular localization
- Cytoplasm
- Nucleus
- The heterodimer is located mainly in the cytosol, and the homodimer in the nucleus.
Alternative names
HSD48, NACA, Nascent polypeptide-associated complex subunit alpha, NAC-alpha, Alpha-NAC