Expression of the AAMP gene, encoding Angio-associated migratory cell protein, is positively regulated by VEGF in a dose- and time-dependent manner through an unknown mechanism (Hu et al. 2016). AAMP was first found to be expressed in blood vessels. High levels of AAMP are found in endothelial cells, cytotrophoblasts and cancer cell lines, and it is typically expressed in cells with a migratory phenotype, including vascular endothelial and smooth muscle cells, renal proximal tubular cells and activated T lymphocytes (Beckner et al. 1995, Beckner et al. 1999). At a subcellular level, AAMP localizes to the cytosol, to the plasma membrane, and to the extracellular matrix (Beckner et al. 1999, Hu et al. 2016). AAMP contains two Ig-homology domains, a putative membrane association domain and six WD40 repeats (Beckner et al. 1995, Reid et al. 2011). The WD40 repeats are predicted to be organized in a beta-propeller architecture, with a disorganized linker region between WD40 repeats 4 and 5 mapping to the putative membrane association domain (Reid et al. 2011).
VEGF facilitates translocation of AAMP to the plasma membrane. Increased AAMP levels and plasma membrane localization can active RHOA signaling and promote cellular migration and angiogenesis (Hu et al. 2016). AAMP-mediated activation of RHOA activity promotes migration of vascular smooth muscle cells and is implicated in hyperplasia of neointima after vascular injury, which contributes to atherosclerosis and restenosis (Vogt et al. 2008).
AAMP promotes migration of HECV cells (human umbilical vein endothelial cell line) and positively regulates expression of VE-cadherin (CDH5) (Yin et al. 2014).