JAM-B/CD322 Protein, Human (HEK293, His)

JAM-B/CD322 protein, a junctional adhesion protein, intricately orchestrates heterotypic cell-cell interactions with its corresponding receptor, JAM3, thereby regulating diverse cellular processes as substantiated by various studies. Its involvement in the homing and mobilization of hematopoietic stem and progenitor cells within the bone marrow underscores its crucial role in this physiological context. Positioned on the surface of bone marrow stromal cells, JAM-B/CD322 contributes significantly to the retention of hematopoietic stem and progenitor cells expressing JAM3. Moreover, this protein assumes a central role in the extravasation of leukocytes by not only facilitating transmigration but also mediating tethering and rolling of leukocytes along the endothelium. The tethering and rolling processes are contingent upon the binding of JAM2 to the integrin alpha-4/beta-1. Beyond hematopoiesis, JAM-B/CD322 extends its influence to spermatogenesis, where interactions between JAM2 and JAM3 in Sertoli and germ cells respectively play a pivotal role in anchoring germ cells onto Sertoli cells and assembling cell polarity complexes during spermatid differentiation. Additionally, it functions as an inhibitory somatodendritic cue, preventing the myelination of non-axonal parts of neurons, contributes to myocyte fusion during myogenesis, and may also play a role in angiogenesis.