Type II Activin Receptor (ActRIIB/ACVR2B) phosphorylates Type I Activin Receptor (ActRIC/ACVR1C) in response to NODAL

As inferred from the response of the activin receptor to activin, the type II component of the NODAL receptor phosphorylates the type I component in response to NODAL binding. As inferred from mouse and frog (Xenopus) NODAL can signal via the ACVR1C (ALK7) type I activin receptor (Reissman et al. 2001) though this may be dispensable for development in mouse (Jornvall et al. 2004).

据此推断，NODAL受体的II型组分在NODAL结合的刺激下对I型组分进行磷酸化，这一过程可从活化素受体对活化素的反应中得出。根据对小鼠和非洲爪蟾（Xenopus）的研究，NODAL可以通过ACVR1C（ALK7）型I活化素受体（Reissman等，2001年）进行信号传导，尽管这一途径在小鼠发育过程中可能并非必不可少（Jornvall等，2004年）。