Interleukin-19 (IL19) binds a heterodimeric receptor complex that consists of Interleukin-20 Receptor subunit alpha (IL20RA) associated with Tyrosine-protein kinase JAK1 (JAK1) and Interleukin-20 receptor subunit beta (IL20RB).
Interleukin-20 receptor A (IL20RA) and Interleukin-20 receptor B (IL20RB) form a receptor complex for Interleukin-19 (IL19) (and Interleukin-20 (IL20) and Interleukin-24 (IL24)) (Gallagher et al. 2000, Blumberg et al. 2001, Parrish-Novak et al. 2002, Logsdon et al. 2012, Rutz et al. 2014, Pletnev et al. 2003).
This is a black box event because it is not clear whether the dimeric receptor can form in the absence of ligand.