Q9NP55 · BPIA1_HUMAN
- ProteinBPI fold-containing family A member 1
- GeneBPIFA1
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids256 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Lipid-binding protein which shows high specificity for the surfactant phospholipid dipalmitoylphosphatidylcholine (DPPC) (PubMed:25223608).
Plays a role in the innate immune responses of the upper airways (PubMed:23132494, PubMed:23499554).
Reduces the surface tension in secretions from airway epithelia and inhibits the formation of biofilm by pathogenic Gram-negative bacteria, such as P.aeruginosa and K.pneumoniae (PubMed:23132494, PubMed:23499554, PubMed:27145151).
Negatively regulates proteolytic cleavage of SCNN1G, an event that is required for activation of the epithelial sodium channel (ENaC), and thereby contributes to airway surface liquid homeostasis and proper clearance of mucus (PubMed:24043776, PubMed:24124190).
Plays a role in the airway inflammatory response after exposure to irritants (PubMed:11425234).
May attract macrophages and neutrophils (PubMed:23132494).
Plays a role in the innate immune responses of the upper airways (PubMed:23132494, PubMed:23499554).
Reduces the surface tension in secretions from airway epithelia and inhibits the formation of biofilm by pathogenic Gram-negative bacteria, such as P.aeruginosa and K.pneumoniae (PubMed:23132494, PubMed:23499554, PubMed:27145151).
Negatively regulates proteolytic cleavage of SCNN1G, an event that is required for activation of the epithelial sodium channel (ENaC), and thereby contributes to airway surface liquid homeostasis and proper clearance of mucus (PubMed:24043776, PubMed:24124190).
Plays a role in the airway inflammatory response after exposure to irritants (PubMed:11425234).
May attract macrophages and neutrophils (PubMed:23132494).
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Cellular Component | extracellular space | |
Molecular Function | lipid binding | |
Biological Process | antibacterial humoral response | |
Biological Process | antimicrobial humoral immune response mediated by antimicrobial peptide | |
Biological Process | defense response to virus | |
Biological Process | immune response in nasopharyngeal-associated lymphoid tissue | |
Biological Process | innate immune response | |
Biological Process | multicellular organismal-level water homeostasis | |
Biological Process | negative regulation of single-species biofilm formation in or on host organism | |
Biological Process | regulation of sodium ion transmembrane transport | |
Biological Process | surfactant homeostasis |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameBPI fold-containing family A member 1
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionQ9NP55
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Note: Apical side of airway epithelial cells. Detected in airway surface liquid, nasal mucus and sputum.
Keywords
- Cellular component
Disease & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 48 | Forms an artificial disulfide bond. Negligible effect on surfactant activity; when associated with C-253. | ||||
Sequence: A → C | ||||||
Mutagenesis | 76 | Forms an artificial disulfide bond. Reduced surfactant activity; when associated with C-214. | ||||
Sequence: I → C | ||||||
Mutagenesis | 87-92 | Impaired surfactant activity and lipopolysaccharide (LPS) binding. Reduced bacteriostatic activity. | ||||
Sequence: LLGGLL → AAGGAA or SSGGSS | ||||||
Mutagenesis | 180 | No effect on surfactant activity; when associated with A-224. | ||||
Sequence: C → A | ||||||
Mutagenesis | 191-195 | No effect on surfactant activity; when associated with 203-A-A-204. | ||||
Sequence: LLDGL → AADGA | ||||||
Mutagenesis | 203-204 | No effect on surfactant activity; when associated with 191-A--A-195. | ||||
Sequence: LL → AA | ||||||
Mutagenesis | 214 | Forms an artificial disulfide bond. Reduced surfactant activity; when associated with C-76. | ||||
Sequence: V → C | ||||||
Mutagenesis | 224 | No effect on surfactant activity; when associated with A-180. | ||||
Sequence: C → A | ||||||
Mutagenesis | 253 | Forms an artificial disulfide bond. Negligible effect on surfactant activity; when associated with C-48. | ||||
Sequence: V → C |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 361 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Genetic variation databases
PTM/Processing
Features
Showing features for signal, chain, disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Signal | 1-19 | |||||
Sequence: MFQTGGLIVFYGLLAQTMA | ||||||
Chain | PRO_0000017175 | 20-256 | BPI fold-containing family A member 1 | |||
Sequence: QFGGLPVPLDQTLPLNVNPALPLSPTGLAGSLTNALSNGLLSGGLLGILENLPLLDILKPGGGTSGGLLGGLLGKVTSVIPGLNNIIDIKVTDPQLLELGLVQSPDGHRLYVTIPLGIKLQVNTPLVGASLLRLAVKLDITAEILAVRDKQERIHLVLGDCTHSPGSLQISLLDGLGPLPIQGLLDSLTGILNKVLPELVQGNVCPLVNEVLRGLDITLVHDIVNMLIHGLQFVIKV | ||||||
Disulfide bond | 180↔224 | |||||
Sequence: CTHSPGSLQISLLDGLGPLPIQGLLDSLTGILNKVLPELVQGNVC |
Post-translational modification
May be N-glycosylated.
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Highly expressed in lung, upper airways and nasopharyngeal regions, including trachea and nasal epithelium (at protein level) (PubMed:11018263, PubMed:11251963, PubMed:11425234, PubMed:12409287, PubMed:26559477).
Specifically expressed in the secretory ducts and submucosal glands of tracheobronchial tissues (at protein level) (PubMed:11425234, PubMed:12409287).
Also expressed in the eye where it is detected in lacrimal gland, eyelid, conjunctiva and cornea (at protein level) (PubMed:26559477).
Specifically localizes to epithelial cell layers in cornea, eyelid (basal epithelium) and conjunctiva (at protein level) (PubMed:26559477).
Detected within acinar cells and ducts in the lacrimal and Meibomian glands (at protein level) (PubMed:26559477).
In lung, shows highest expression in the trachea and progressive decrease from proximal (bronchial) to distal (bronchiolar) airways (PubMed:12409287).
Also expressed in lung cancers and some other types of cancer (PubMed:11251963).
Specifically expressed in the secretory ducts and submucosal glands of tracheobronchial tissues (at protein level) (PubMed:11425234, PubMed:12409287).
Also expressed in the eye where it is detected in lacrimal gland, eyelid, conjunctiva and cornea (at protein level) (PubMed:26559477).
Specifically localizes to epithelial cell layers in cornea, eyelid (basal epithelium) and conjunctiva (at protein level) (PubMed:26559477).
Detected within acinar cells and ducts in the lacrimal and Meibomian glands (at protein level) (PubMed:26559477).
In lung, shows highest expression in the trachea and progressive decrease from proximal (bronchial) to distal (bronchiolar) airways (PubMed:12409287).
Also expressed in lung cancers and some other types of cancer (PubMed:11251963).
Induction
Up-regulated in response to all-trans retinoic acid (ATRA) (PubMed:12409287).
Up-regulated in tear fluid of patients suffering from dry eye disease (PubMed:26559477).
Up-regulated in response to the pro-inflammatory cytokines IL1B and TNF, and the bacteria E.coli and P.aeruginosa (PubMed:26559477).
Up-regulated in tear fluid of patients suffering from dry eye disease (PubMed:26559477).
Up-regulated in response to the pro-inflammatory cytokines IL1B and TNF, and the bacteria E.coli and P.aeruginosa (PubMed:26559477).
Gene expression databases
Organism-specific databases
Interaction
Subunit
Monomer. Interacts (via N-terminus) with SCNN1B, a subunit of the heterotrimeric epithelial sodium channel (ENaC); this inhibits proteolytic activation of ENaC.
Binary interactions
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 87-92 | Important for surfactant activity and antibacterial properties | ||||
Sequence: LLGGLL |
Sequence similarities
Belongs to the BPI/LBP/Plunc superfamily. Plunc family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
- Sequence processingThe displayed sequence is further processed into a mature form.
This entry describes 2 isoforms produced by Alternative splicing.
Q9NP55-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length256
- Mass (Da)26,713
- Last updated2000-10-01 v1
- ChecksumEDF152FBC35315BC
Q9NP55-2
- Name2
- Differences from canonical
- 16-29: Missing
Features
Showing features for alternative sequence, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_057345 | 16-29 | in isoform 2 | |||
Sequence: Missing | ||||||
Sequence conflict | 220 | in Ref. 1; AAF70860 | ||||
Sequence: Q → K |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AF214562 EMBL· GenBank· DDBJ | AAG13653.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF172993 EMBL· GenBank· DDBJ | AAF70860.1 EMBL· GenBank· DDBJ | mRNA | ||
AF158745 EMBL· GenBank· DDBJ | AAF82622.1 EMBL· GenBank· DDBJ | mRNA | ||
AB024937 EMBL· GenBank· DDBJ | BAA93633.1 EMBL· GenBank· DDBJ | mRNA | ||
AF439448 EMBL· GenBank· DDBJ | AAL87636.1 EMBL· GenBank· DDBJ | mRNA | ||
AF417256 EMBL· GenBank· DDBJ | AAO12198.1 EMBL· GenBank· DDBJ | mRNA | ||
AF417257 EMBL· GenBank· DDBJ | AAO12199.1 EMBL· GenBank· DDBJ | mRNA | ||
AF421369 EMBL· GenBank· DDBJ | AAO12200.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AY359020 EMBL· GenBank· DDBJ | AAQ89379.1 EMBL· GenBank· DDBJ | mRNA | ||
AK292778 EMBL· GenBank· DDBJ | BAF85467.1 EMBL· GenBank· DDBJ | mRNA | ||
DQ846869 EMBL· GenBank· DDBJ | ABI63356.1 EMBL· GenBank· DDBJ | mRNA | ||
AL121901 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
CH471077 EMBL· GenBank· DDBJ | EAW76327.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471077 EMBL· GenBank· DDBJ | EAW76328.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471077 EMBL· GenBank· DDBJ | EAW76329.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC012549 EMBL· GenBank· DDBJ | AAH12549.1 EMBL· GenBank· DDBJ | mRNA |