BMPR1AALK3

BMPR1AALK3 is a naming variant that refers to the bone morphogenetic protein receptor type 1A, also known as activin receptor-like kinase 3 (ALK3). In standard nomenclature ALK3 and BMPR1A designate the same type I BMP receptor, a single transmembrane serine/threonine kinase that partners with type II BMP receptors to convey signals for bone morphogenesis and other developmental processes. The term BMPR1AALK3 may appear in databases or articles as a fused or concatenated symbol, but it does not indicate a distinct gene product; it reflects aliasing between BMPR1A and ALK3.

The BMPR1A/ALK3 receptor binds BMP ligands, forms a heteromeric complex with type II receptors, and autophosphorylates in its kinase domain. Activated SMAD1/5/8 are phosphorylated, partner with SMAD4, and regulate transcription of target genes involved in osteogenesis, embryonic development, and tissue homeostasis. The receptor is expressed in multiple tissues, with particularly critical roles in skeletal formation and development.

Genetic variation in BMPR1A is associated with juvenile polyposis syndrome when loss-of-function mutations occur, highlighting its role in gastrointestinal mucosal growth control. Altered BMP signaling has also been observed in various cancers and developmental disorders, making the BMPR1A/ALK3 axis a subject of research for potential diagnostic and therapeutic applications.

See also: BMPR1A, ALK3, BMP signaling, juvenile polyposis syndrome.