Protein: Pulmonary surfactant-associated protein A1 (PSP-A) (PSPA) (SP-A) (SP-A1) (35 kDa pulmonary surfactant-associated protein) (Alveolar proteinosis protein) (Collectin-4) (Q8IWL2)
Organism: Homo sapiens (Human)
Function: In presence of calcium ions, it binds to surfactant phospholipids and contributes to lower the surface tension at the air-liquid interface in the alveoli of the mammalian lung and is essential for normal respiration. Enhances the expression of MYO18A/SP-R210 on alveolar macrophages (By similarity).
Subcellular location: Secreted {ECO:0000269|PubMed:26792177, ECO:0000269|PubMed:32855221}. Secreted, extracellular space, extracellular matrix {ECO:0000305}. Secreted, extracellular space, surface film {ECO:0000305}.
Sequence: MWLCPLALNLILMAASGAVCEVKDVCVGSPGIPGTPGSHGLPGRDGRDGLKGDPGPPGPMGPPGEMPCPPGNDGLPGAPGIPGECGEKGEPGERGPPGLPAHLDEELQATLHDFRHQILQTRGALSLQGSIMTVGEKVFSSNGQSITFDAIQEACARAGGRIAVPRNPEENEAIASFVKKYNTYAYVGLTEGPSPGDFRYSDGTPVNYTNWYRGEPAGRGKEQCVEMYTDGQWNDRNCLYSRLTICEF
InterPro domains: - IPR051663: C-type lectin and Tetranectin domain-containing protein (family) [105-248]
- IPR016186: C-type lectin-like/link domain superfamily (homologous_superfamily) [101-248]
- IPR018378: C-type lectin, conserved site (conserved_site) [224-246]
- IPR033990: Collectin, C-type lectin-like domain (domain) [136-248]
- IPR016187: C-type lectin fold (homologous_superfamily) [135-248]
- IPR001304: C-type lectin-like (domain) [126-248]
Interaction partners: - Surfactant protein C
- Pulmonary surfactant-associated protein B
- Surfactant protein A2
- Secretoglobin family 3A member 2
- Pulmonary surfactant-associated protein D
- Uteroglobin
- Homeobox protein Nkx-2.1
- Lactotransferrin
- Deleted in malignant brain tumors 1 protein
- Advanced glycosylation end product-specific receptor
Gene Ontology annotations:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0005515 (protein binding)
Biological Process (BP): GO:0008150 (biological process), GO:0065007 (biological regulation), GO:0048518 (positive regulation of biological process), GO:0050896 (response to stimulus), GO:0050789 (regulation of biological process), GO:0044419 (biological process involved in interspecies interaction between organisms), GO:0002376 (immune system process), GO:0009605 (response to external stimulus), GO:0048584 (positive regulation of response to stimulus), GO:0009607 (response to biotic stimulus), GO:0006955 (immune response), GO:0032879 (regulation of localization), GO:0002684 (positive regulation of immune system process), GO:0050794 (regulation of cellular process), GO:0048583 (regulation of response to stimulus), GO:0002682 (regulation of immune system process), GO:0002252 (immune effector process), GO:0006950 (response to stress), GO:0002253 (activation of immune response), GO:0044403 (biological process involved in symbiotic interaction), GO:0051050 (positive regulation of transport), GO:0051707 (response to other organism), GO:0051049 (regulation of transport), GO:0050776 (regulation of immune response), GO:0043207 (response to external biotic stimulus), GO:0051702 (biological process involved in interaction with symbiont), GO:0009617 (response to bacterium), GO:0006959 (humoral immune response), GO:0050766 (positive regulation of phagocytosis), GO:0006952 (defense response), GO:0050778 (positive regulation of immune response), GO:0060627 (regulation of vesicle-mediated transport), GO:0006956 (complement activation), GO:0045087 (innate immune response), GO:0098542 (defense response to other organism), GO:0050764 (regulation of phagocytosis), GO:0042742 (defense response to bacterium), GO:0051873 (killing by host of symbiont cells), GO:0050830 (defense response to Gram-positive bacterium)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0016020 (membrane), GO:0031984 (organelle subcompartment), GO:0005737 (cytoplasm), GO:0012505 (endomembrane system), GO:0005576 (extracellular region), GO:0031090 (organelle membrane), GO:0030141 (secretory granule), GO:0031410 (cytoplasmic vesicle), GO:0043229 (intracellular organelle), GO:0098827 (endoplasmic reticulum subcompartment), GO:0042175 (nuclear outer membrane-endoplasmic reticulum membrane network), GO:0005783 (endoplasmic reticulum), GO:0043227 (membrane-bounded organelle), GO:0030139 (endocytic vesicle), GO:0099503 (secretory vesicle), GO:0043231 (intracellular membrane-bounded organelle), GO:0030135 (coated vesicle), GO:0042599 (lamellar body), GO:0005789 (endoplasmic reticulum membrane), GO:0031982 (vesicle), GO:0097708 (intracellular vesicle), GO:0030136 (clathrin-coated vesicle), GO:0045334 (clathrin-coated endocytic vesicle)