Mouse P-Selectin, alternatively known as GMP-140, LECAM-3, PADGEM, or CD62P, belongs to the Selectin family of cell surface glycoproteins. It is expressed by activated platelets and endothelial cells. The Mouse P-Selectin cDNA encodes a 768 amino acid (aa) type I transmembrane protein, which includes a 41 aa signal peptide, a 668 aa extracellular domain, a transmembrane domain, and a short (35 aa) cytoplasmic domain.
The extracellular domain of Mouse P-Selectin contains an NH2-terminal C-type lectin domain and an EGF-like domain, followed by a series of complement factor A repeat homology domains. It shares approximately 73% sequence homology with the extracellular domains of human P-Selectin.
Mouse P-Selectin plays a critical role in the adhesion of leukocytes and neutrophils to the endothelium. Together with L-Selectin, it initiates the interaction between circulating leukocytes and endothelial cells, leading to the characteristic 'rolling' of leukocytes along the endothelium. This initial interaction is followed by the formation of a stronger bond involving E-Selectin, and subsequently ICAM-1 and VCAM-1. This sequence of molecular interactions facilitates the extravasation of white blood cells through the blood vessel wall and into the extracellular matrix of surrounding tissues.