(PP)2-IP4 is dephosphorylated to 5-PP-IP5 by NUDT(1) in the cytosol

Diphosphoinositol polyphosphate phosphohydrolases (DIPP), also known as nucleoside diphosphate-linked moiety X motif (NUDT) proteins, dephosphorylate inositol bisdiphospho-tetrakisphosphate ((PP)2-IP4) to inositol 5-diphospho-1,2,3,4,6-pentakisphosphate (5-PP-IP5). The NUDT proteins involved are: nucleoside diphosphate-linked moiety X motif 3 (NUDT3), 4 (NUDT4), 10 (NUDT10), and 11 (NUDT11). The reactants consumed are: inositol 1,5-bisdiphospho-2,3,4,6-tetrakisphosphate (1,5-(PP)2-IP4) and inositol 3,5-bisdiphospho-1,2,4,6-tetrakisphosphate (3,5-(PP)2-IP4).<br><br>The following lists the above proteins with their corresponding literature references: NUDT3 (Safrany et al. 1999, Safrany et al. 1998, Yang et al. 1999, Caffrey et al. 2000), NUDT4 (Caffrey et al. 2000), NUDT10 (Leslie et al. 2002, Hidaka et al. 2002) and NUDT11 (Leslie et al. 2002, Hidaka et al. 2002).

双磷酰肌醇多磷酸磷酸水解酶（Diphosphoinositol polyphosphate phosphohydrolases，简称DIPP），亦称核苷二磷酸连接基团X结构域（nucleoside diphosphate-linked moiety X motif，简称NUDT）蛋白，通过去磷酸化肌醇双磷酰四磷酸（inositol bisdiphospho-tetrakisphosphate，(PP)2-IP4）生成肌醇5-二磷酸-1,2,3,4,6-五磷酸（inositol 5-diphospho-1,2,3,4,6-pentakisphosphate，5-PP-IP5）。涉及的NUDT蛋白包括：核苷二磷酸连接基团X结构域3（nucleoside diphosphate-linked moiety X motif 3，NUDT3）、4（NUDT4）、10（NUDT10）和11（NUDT11）。消耗的反应物为肌醇1,5-双磷酰二磷酸-2,3,4,6-四磷酸（inositol 1,5-bisdiphospho-2,3,4,6-tetrakisphosphate，1,5-(PP)2-IP4）和肌醇3,5-双磷酰二磷酸-1,2,4,6-四磷酸（inositol 3,5-bisdiphospho-1,2,4,6-tetrakisphosphate，3,5-(PP)2-IP4）。以下列出了上述蛋白及其对应的文献引用：NUDT3（Safrany et al. 1999，Safrany et al. 1998，Yang et al. 1999，Caffrey et al. 2000），NUDT4（Caffrey et al. 2000），NUDT10（Leslie et al. 2002，Hidaka et al. 2002）和NUDT11（Leslie et al. 2002，Hidaka et al. 2002）。