InterPro domain: IPR038922

HYPK, also called Huntingtin yeast partner K or Huntingtin yeast two-hybrid protein K, is an intrinsically unstructured Huntingtin (HTT)-interacting protein with chaperone-like activity. It is involved in regulating cell growth, cell cycle, unfolded protein response, and cell death [ 1 , 2 , 3 ]. Proteins matched by this entry contain an N-terminal ubiquitin-associated (UBA) region that shows high sequence similarity with that of eukaryotic nascent polypeptide-associated complex proteins (NAC), which is one of the cytosolic chaperones that contact the nascent polypeptide chains as they emerge from the ribosome and assist in post-translational processes [ 4 , 5 ].

1. Huntingtin interacts with a family of WW domain proteins. Hum. Mol. Genet. 7, 1463-74
2. Identification of HYPK-interacting proteins reveals involvement of HYPK in regulating cell growth, cell cycle, unfolded protein response and cell death. PLoS ONE 7, e51415
3. Huntingtin interacting protein HYPK is intrinsically unstructured. Proteins 71, 1686-98
4. The chaperone-like protein HYPK acts together with NatA in cotranslational N-terminal acetylation and prevention of Huntingtin aggregation. Mol. Cell. Biol. 30, 1898-909
5. HYPK, a Huntingtin interacting protein, reduces aggregates and apoptosis induced by N-terminal Huntingtin with 40 glutamines in Neuro2a cells and exhibits chaperone-like activity. Hum. Mol. Genet. 17, 240-55