In the preclinical data presented at the ASBMR meeting, BLU-782 demonstrated exquisite selectivity for R206H mutant ALK2 in cellular assays, while sparing closely related anti-targets including ALK1, ALK3, and ALK6
. Additionally, BLU-782 potently inhibited mutant ALK2 in vitro, regardless of the activating ligand, including Activin A, Activin B and BMP6.
To act in adjacent cells to the oocyte, the GDF9 binds to the TGF-[beta] receptor type I (ALK5) (Moore et al., 2003; Mazerbourg et al., 2004; Huang et al., 2009) and BMPRII (Vitt et al., 2002), while the BMP15 binds to BMP receptor type IB (ALK6
) and to the BMPRII (Peng et al., 2013).
BMP-15 es expresado principalmente en el ovocito y reconocido por receptores BMPRIB (ALK6
) en las celulas de la teca y del cumulus [11, 13, 16].
A nivel de superficie celular, el dimero de BMP se une al receptor tipo I (activin receptor-like kinase; ALK2, ALK3, o ALK6
) y al receptor tipo II (BMPR-II, ActR-IIA, o ActRIIB) para la formacion de complejos heteromericos.
Highly prolific Booroola sheep have a mutation in the intracellular kinase domain of bone morphogenetic protein IB re captor (ALK6
) that is expressed in both oocytes and granulosa cells.
The disulfide-linked mature dimer of BMPs will associate with membrane receptors that have been identified as type I receptors--BMPRIA (or activin receptor-like kinase 3--ALK3) and BMPRIB (or ALK6
), and type II receptor--BMPRII (Yamashita et al.
In sheep, three prolificacy loci have been discovered, namely bone morphogenetic protein receptor type 1B (BMPR1B; or activin-like kinase 6, ALK6
), known as FecB (Booroola) on chromosome 6 (Souza et al., 2001) corresponding to the human chromosome 4q22-23 (Montgomery et al., 1993); growth differentiation factor 9 (GDF9), known as FecG on chromosome 5 (Hanrahan et al., 2004); and bone morphogenetic protein 15 (BMP15) known as FecX on chromosome X (Hanrahan et al., 2004; Galloway et al., 2000).