Sanders Shaun S, Mui Katherine K N, Sutton Liza M, Hayden Michael R
Department of Medical Genetics and Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
PLoS One. 2014 Feb 28;9(2):e90669. doi: 10.1371/journal.pone.0090669. eCollection 2014.
Huntington disease is an adult onset neurodegenerative disease characterized by motor, cognitive, and psychiatric dysfunction, caused by a CAG expansion in the HTT gene. Huntingtin Interacting Protein 14 (HIP14) and Huntingtin Interacting Protein 14-like (HIP14L) are palmitoyl acyltransferases (PATs), enzymes that mediate the post-translational addition of long chain fatty acids to proteins in a process called palmitoylation. HIP14 and HIP14L interact with and palmitoylate HTT and are unique among PATs as they are the only two that have an ankyrin repeat domain, which mediates the interaction between HIP14 and HTT. These enzymes show reduced interaction with and palmitoylation of mutant HTT, leading to increased mutant HTT inclusion formation and toxicity. The interaction between HIP14 and HTT goes beyond that of only an enzyme-substrate interaction as HTT is essential for the full enzymatic activity of HIP14. It is important to further understand and characterize the interactions of HTT with HIP14 and HIP14L to guide future efforts to target and enhance this interaction and increase enzyme activity to remediate palmitoylation of HTT and their substrates, as well as to understand the relationship between the three proteins. HIP14 and HIP14L have been previously shown to interact with HTT amino acids 1-548. Here the interaction of HIP14 and HIP14L with N- and C-terminal HTT 1-548 deletion mutations was assessed. We show that HTT amino acids 1-548 were sufficient for full interaction of HTT with HIP14 and HIP14L, but partial interaction was also possible with HTT 1-427 and HTT 224-548. To further characterize the binding domain we assessed the interaction of HIP14-GFP and HIP14L-GFP with 15Q HTT 1-548Δ257-315. Both enzymes showed reduced but not abolished interaction with 15Q HTT 1-548Δ257-315. This suggests that two potential binding domains exist, one around residues 224 and the other around 427, for the PAT enzymes HIP14 and HIP14L.
亨廷顿病是一种成年发病的神经退行性疾病，其特征为运动、认知和精神功能障碍，由HTT基因中的CAG重复扩增引起。亨廷顿相互作用蛋白14（HIP14）和亨廷顿相互作用蛋白14样蛋白（HIP14L）是棕榈酰酰基转移酶（PATs），这类酶在一个称为棕榈酰化的过程中介导长链脂肪酸在蛋白质上的翻译后添加。HIP14和HIP14L与HTT相互作用并使其棕榈酰化，在PATs中它们是独特的，因为它们是仅有的两个具有锚蛋白重复结构域的酶，该结构域介导HIP14与HTT之间的相互作用。这些酶与突变型HTT的相互作用及对其棕榈酰化作用减弱，导致突变型HTT包涵体形成增加和毒性增强。HIP14与HTT之间的相互作用不仅仅是酶 - 底物相互作用，因为HTT对HIP14的完整酶活性至关重要。进一步了解和表征HTT与HIP14及HIP14L之间的相互作用，对于指导未来靶向和增强这种相互作用、提高酶活性以修复HTT及其底物的棕榈酰化作用，以及理解这三种蛋白质之间的关系非常重要。先前已表明HIP14和HIP14L与HTT的1 - 548位氨基酸相互作用。在此评估了HIP14和HIP14L与N端和C端HTT 1 - 548缺失突变体的相互作用。我们发现HTT的1 - 548位氨基酸足以使HTT与HIP14和HIP14L充分相互作用，但HTT 1 - 427和HTT 224 - 548也可能发生部分相互作用。为了进一步表征结合结构域，我们评估了HIP14 - GFP和HIP14L - GFP与15Q HTT 1 - 548Δ257 - 315的相互作用。两种酶与15Q HTT 1 - 548Δ257 - 315的相互作用均减弱但未消除。这表明对于PAT酶HIP14和HIP14L存在两个潜在的结合结构域，一个在224位残基附近，另一个在427位残基附近。
Zotero 插件