The calx-β motif is present as a tandem repeat in the cytoplasmic domains of Calx Na-Ca exchangers, which are used to expel calcium from cells. This motif overlaps domains used for calcium binding and regulation. The calx-β motif is also present in the cytoplasmic tail of mammalian integrin-beta4, which mediates the bi-directional transfer of signals across the plasma membrane, as well as in … expand

The calx-β motif is present as a tandem repeat in the cytoplasmic domains of Calx Na-Ca exchangers, which are used to expel calcium from cells. This motif overlaps domains used for calcium binding and regulation. The calx-β motif is also present in the cytoplasmic tail of mammalian integrin-beta4, which mediates the bi-directional transfer of signals across the plasma membrane, as well as in some cyanobacterial proteins. This motif is also found in Fras1/Frem family of extracellular proteins (extracellular matrix organizing protein FRAS1 and FRAS1-related extracellular matrix proteins FRAM1, 2 and 3) required for proper organogenesis during embryonic development and whose mutations lead to Fraser Syndrome, a rare congenital disorder characterised by multisystem malformation usually comprising abnormal brain formation, cryptophthalmos, syndactyly and renal defects [ PUBMED:32333816 ]. This motif contains a series of β-strands and turns that form a self-contained β-sheet [ PUBMED:9294196 PUBMED:10390612 ].