RAP1B

Function

GTP-binding protein that possesses intrinsic GTPase activity. Contributes to the polarizing activity of KRIT1 and CDH5 in the establishment and maintenance of correct endothelial cell polarity and vascular lumen. Required for the localization of phosphorylated PRKCZ, PARD3 and TIAM1 to the cell junction. Plays a role in the establishment of basal endothelial barrier function.

Involvement in disease

Thrombocytopenia 11 with multiple congenital anomalies and dysmorphic facies

THC11

A form of thrombocytopenia, a hematologic disorder defined by a decrease in the number of platelets in circulating blood, resulting in the potential for increased bleeding and decreased ability for clotting. THC11 is an autosomal dominant, syndromic form. Affected individuals have chronic and persistent thrombocytopenia, dysmorphic facial features, and multiple congenital anomalies with involvement of the cardiovascular, genitourinary, neurologic and skeletal systems. Additional features include leukopenia or anemia, poor growth with microcephaly, hypotonia, and mildly impaired intellectual development or learning disabilities.

None

The disease is caused by variants affecting the gene represented in this entry.

Sequence Similarities

Belongs to the small GTPase superfamily. Ras family.

Cellular localization

• Cell membrane
• Cytoplasm
• Cytosol
• Cell junction
• May shuttle between plasma membrane and cytosol (PubMed:3141412). Presence of KRIT1 and CDH5 is required for its localization to the cell junction (PubMed:20332120).

Alternative names

OK/SW-cl.11, RAP1B, Ras-related protein Rap-1b, GTP-binding protein smg p21B

Database links

swissprot:P61224 omim:179530 omim:RAP1B swissprot:P62834 entrezGene:5906 entrezGene:5908 omim:179520