RAP1A gene

The RAP1A gene (RAP1A stands for: Ras-Related Protein-1A) is a protein-coding gene located on chromosome 1p13.2. Pseudogenes of this gene have been defined on chromosomes 14 and 17. Alternative splicing leads to several transcript variants. An important paralog of this gene is RAP1B.

The RAP1A gene encodes a member of the Ras family of small GTPases. The encoded protein changes its conformational state and activity depending on whether it is bound to GTP or GDP. This protein is activated by several types of guanine nucleotide exchange factors (GEFs) and inactivated by two groups of GTPase-activating proteins (GAPs). The activation status of the encoded protein is therefore influenced by the balance of intracellular concentrations of GEFs and GAPs. The encoded protein regulates signaling pathways that influence cell proliferation and adhesion and may play a role in oncogenesis.

Diseases associated with RAP1A include:

Tuberous sclerosis

and

Immunodeficiency-54.

The protein of the same name encoded by the RAP1A gene induces morphological reversion of a cell line transformed by a Ras oncogene. RAP1A counteracts the mitogenic function of Ras, at least in part, because it can interact with Ras GAPs and RAF in a competitive manner. Together with ITGB1BP1, regulates the localization of KRIT1 to microtubules and membranes. RAP1A plays a role in nerve growth factor (NGF)-induced neurite outgrowth. The protein plays a role in the regulation of embryonic blood vessel formation and is involved in the establishment of the basal endothelial barrier function. It may be involved in regulating the expression of the vascular endothelial growth factor receptor KDR at endothelial cell-cell junctions.

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