NOTUM releases Hh-Np:GPC5 from the plasma membrane

Notum is a secreted protein with phospholipase C activity that has been implicated in promoting long range Hh signaling in Drosophila (Ayers et al, 2010; Eugster et al, 2007; Takeo et al, 2005; Han et al, 2005; Giraldez et al, 2002). Notum is thought to cleave the GPI-anchor from Dally, a Drosophila glypican, to release Hh-Dally complexes from the plasma membrane of the Hh-secreting cell (Ayers et al, 2010; Han et al, 2005), although this cleavage has not been directly demonstrated. In cultured mammalian cells, NOTUM has been shown to cleave the GPI anchor of a number of glypicans to promote their release from the plasma membrane (Traister et al, 2008).

Notum是一种具有磷脂酶C活性的分泌蛋白，其在果蝇中促进长距离Hh信号传导的作用已被证实（Ayers等，2010；Eugster等，2007；Takeo等，2005；Han等，2005；Giraldez等，2002）。据推测，Notum能够切割Dally的GPI-锚，Dally是一种果蝇糖蛋白，从而释放Hh-Dally复合物从分泌Hh的细胞的质膜中（Ayers等，2010；Han等，2005），尽管这一切割过程尚未得到直接证实。在培养的人源细胞中，NOTUM已被证明能够切割多种糖蛋白的GPI锚，以促进其从质膜上的释放（Traister等，2008）。