RHOA

A gene on chromosome 3p21.3 that encodes a protein with multiple functions: it regulates a signal transduction pathway, linking plasma membrane receptors to the assembly of focal adhesions and actin stress fibres; it is involved in a microtubule-dependent signal required for myosin contractile ring formation during cell cycle cytokinesis; it plays an essential role in cleavage furrow formation; and it is required for the apical junction formation of keratinocyte cell-cell adhesion. RHOA is activated by ARHGEF2, which promotes GDP for GTP exchange, and is essential for the SPATA13-mediated regulation of cell migration and adhesion assembly and disassembly. The MEMO1-RHOA-DIAPH1 signalling pathway plays a key role in ERBB2-dependent stabilisation of microtubules at the cell cortex. It controls the localisation of APC and CLASP2 to the cell membrane by regulating GSK3B activity; membrane-bound APC allows the localisation of the MACF1 to the cell membrane, as required for microtubule capture and stabilisation.