Guanine nucleotide-binding proteins (G proteins) are involved as a modulator or transducer in various transmembrane signaling systems. The beta and gamma chains are required for the GTPase activity, for replacement of GDP by GTP, and for G protein-effector interaction. G proteins are composed of 3 units, alpha, beta and gamma. Strongly expressed in lung and placenta, whereas it is weakly expressed in brain and heart. Abundantly expressed in the axons and Schwann cells of peripheral nerves. The disease is caused by variants affecting the gene represented in this entry. Belongs to the WD repeat G protein beta family.