Surfactant protein A2 (SFTPA2)

Surfactant protein A2 (SFTPA2) is a member of the collectin family and is encoded by the SFTPA2 gene on chromosome 10q22.3[2][1]. It is one of two closely related human surfactant protein A isoforms, the other being SFTPA1. SFTPA2 is a crucial protein in the lung, serving dual roles in lowering alveolar surface tension by binding surfactant phospholipids and in modulating innate immune defense by interacting with alveolar macrophages and pattern recognition on pathogens[2][1][3]. Structurally, SFTPA2 is a secreted protein forming oligomeric assemblies, with a signal peptide, collagen-like domain, neck, and C-terminal carbohydrate recognition domain. Compared to SP-A1, SP-A2 differs by a small number of amino acids, most notably at position 85, leading to subtle structural and functional differences between these isoforms[1][3][4]. SP-A2 is linked to immune modulation, surfactant structural integrity, and disease susceptibility, particularly interstitial lung diseases and idiopathic pulmonary fibrosis, especially when genetic variants affect its function[2]. SFTPA2 is not currently a direct drug target, but its role is under research in disease biomarker development and as a potential agent for protein or gene therapy in lung disease[1][2][3].

Other names

Pulmonary surfactant-associated protein A2COLEC5PSAPSFTP1SFTPASFTPA2BPSP-APSPASP-ASP-A235 kDa pulmonary surfactant-associated proteinAlveolar proteinosis proteinCollectin-5surfactant pulmonary-associated protein A2AILD2SP-2ASPA2SPAII

Not applicable (no approved drugs directly target SFTPA2 itself); indirect mechanisms involve modulation of immune responses and surfactant function