This gene encodes a small GTP-binding protein of the Rab GTPase family, whose members function in vesicle transport during protein secretion and endocytosis. Rab GTPases are active, membrane-associated proteins that recruit effector proteins in the GTP-bound state and inactive cytosolic proteins when in a GDP-bound state. The protein encoded by this gene is ubiquitously expressed and has been implicated in Golgi to endoplasmic reticulum cycling of Golgi enzymes. In addition, this protein regulates Golgi homeostasis and coordinates intra-Golgi retrograde trafficking. Allelic variants in this gene have been associated with Dyggve-Melchior-Clausen syndrome and Smith-McCort dysplasia 2, which are autosomal recessive spondyloepimetaphyseal dysplasias characterized by skeletal abnormalities. [From RefSeq]