PSPB_HUMAN
ID PSPB_HUMAN Reviewed; 381 AA.
AC P07988; Q96R04;
DT 01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-MAY-1992, sequence version 3.
DT 03-AUG-2022, entry version 218.
DE RecName: Full=Pulmonary surfactant-associated protein B;
DE Short=SP-B;
DE AltName: Full=18 kDa pulmonary-surfactant protein;
DE AltName: Full=6 kDa protein;
DE AltName: Full=Pulmonary surfactant-associated proteolipid SPL(Phe);
DE Flags: Precursor;
GN Name=SFTPB; Synonyms=SFTP3;
OS Homo sapiens (Human).
OC Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC Homo.
OX NCBI_TaxID=9606;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], AND PROTEIN SEQUENCE OF 201-214.
RC TISSUE=Lung;
RX PubMed=3597440; DOI=10.1016/s0021-9258(18)48005-2;
RA Jacobs K.A., Phelps D.S., Steinbrink R., Fisch J., Kriz R., Mitsock L.,
RA Dougherty J.P., Taeusch H.W., Floros J.;
RT "Isolation of a cDNA clone encoding a high molecular weight precursor to a
RT 6-kDa pulmonary surfactant-associated protein.";
RL J. Biol. Chem. 262:9808-9811(1987).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND VARIANT ARG-228.
RX PubMed=2924687; DOI=10.1089/dna.1.1989.8.75;
RA Pilot-Matias T.J., Kister S.E., Fox J.L., Kropp K., Glasser S.W.,
RA Whitsett J.A.;
RT "Structure and organization of the gene encoding human pulmonary surfactant
RT proteolipid SP-B.";
RL DNA 8:75-86(1989).
RN [3]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND VARIANTS ILE-131; PHE-176 AND
RP HIS-272.
RG SeattleSNPs variation discovery resource;
RL Submitted (JUL-2001) to the EMBL/GenBank/DDBJ databases.
RN [4]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC TISSUE=Brain;
RX PubMed=15489334; DOI=10.1101/gr.2596504;
RG The MGC Project Team;
RT "The status, quality, and expansion of the NIH full-length cDNA project:
RT the Mammalian Gene Collection (MGC).";
RL Genome Res. 14:2121-2127(2004).
RN [5]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 99-381, AND VARIANT ARG-228.
RX PubMed=3035561; DOI=10.1073/pnas.84.12.4007;
RA Glasser S.W., Korfhagen T.R., Weaver T., Pilot-Matias T., Fox J.L.,
RA Whitsett J.A.;
RT "cDNA and deduced amino acid sequence of human pulmonary surfactant-
RT associated proteolipid SPL(Phe).";
RL Proc. Natl. Acad. Sci. U.S.A. 84:4007-4011(1987).
RN [6]
RP NUCLEOTIDE SEQUENCE [MRNA] OF 139-381.
RX PubMed=3343343; DOI=10.1172/jci113391;
RA Revak S.D., Merritt T.A., Degryse E., Stefani L., Courtney M., Hallman M.,
RA Cochrane C.G.;
RT "Use of human surfactant low molecular weight apoproteins in the
RT reconstitution of surfactant biologic activity.";
RL J. Clin. Invest. 81:826-833(1988).
RN [7]
RP PROTEIN SEQUENCE OF 201-279, DISULFIDE BONDS, AND VARIANT ILE-228.
RX PubMed=1568474; DOI=10.1016/0014-5793(92)81239-i;
RA Johansson J., Joernvall H., Curstedt T.;
RT "Human surfactant polypeptide SP-B. Disulfide bridges, C-terminal end, and
RT peptide analysis of the airway form.";
RL FEBS Lett. 301:165-167(1992).
RN [8]
RP STRUCTURE BY FTIR OF 201-225.
RX PubMed=10798379; DOI=10.1034/j.1399-3011.2000.00693.x;
RA Gordon L.M., Lee K.Y., Lipp M.M., Zasadzinski J.A., Walther F.J.,
RA Sherman M.A., Waring A.J.;
RT "Conformational mapping of the N-terminal segment of surfactant protein B
RT in lipid using 13C-enhanced Fourier transform infrared spectroscopy.";
RL J. Pept. Res. 55:330-347(2000).
RN [9]
RP STRUCTURE BY NMR OF 208-278.
RX PubMed=17845058; DOI=10.1021/bi7011756;
RA Sarker M., Waring A.J., Walther F.J., Keough K.M., Booth V.;
RT "Structure of mini-B, a functional fragment of surfactant protein B, in
RT detergent micelles.";
RL Biochemistry 46:11047-11056(2007).
RN [10]
RP VARIANT SMDP1 CYS-236.
RX PubMed=7491219;
RA Ballard P.L., Nogee L.M., Beers M.F., Ballard R.A., Planer B.C., Polk L.,
RA deMello D.E., Moxley M.A., Longmore W.J.;
RT "Partial deficiency of surfactant protein B in an infant with chronic lung
RT disease.";
RL Pediatrics 96:1046-1052(1995).
RN [11]
RP VARIANT ILE-131.
RX PubMed=11076040; DOI=10.1034/j.1399-0004.2000.580305.x;
RA Lin Z., Pearson C., Chinchilli V., Pietschmann S.M., Luo J., Pison U.,
RA Floros J.;
RT "Polymorphisms of human SP-A, SP-B, and SP-D genes: association of SP-B
RT Thr131Ile with ARDS.";
RL Clin. Genet. 58:181-191(2000).
RN [12]
RP INVOLVEMENT IN SUSCEPTIBILITY TO RDS.
RX PubMed=11063734; DOI=10.1093/hmg/9.18.2751;
RA Haataja R., Raemet M., Marttila R., Hallman M.;
RT "Surfactant proteins A and B as interactive genetic determinants of
RT neonatal respiratory distress syndrome.";
RL Hum. Mol. Genet. 9:2751-2760(2000).
CC -!- FUNCTION: Pulmonary surfactant-associated proteins promote alveolar
CC stability by lowering the surface tension at the air-liquid interface
CC in the peripheral air spaces. SP-B increases the collapse pressure of
CC palmitic acid to nearly 70 millinewtons per meter.
CC -!- SUBUNIT: Homodimer; disulfide-linked. {ECO:0000269|PubMed:1568474}.
CC -!- INTERACTION:
CC P07988; Q6FHY5: MEOX2; NbExp=3; IntAct=EBI-14955352, EBI-16439278;
CC -!- SUBCELLULAR LOCATION: Secreted, extracellular space, surface film.
CC -!- DISEASE: Pulmonary surfactant metabolism dysfunction 1 (SMDP1)
CC [MIM:265120]: A rare lung disorder due to impaired surfactant
CC homeostasis. It is characterized by alveolar filling with floccular
CC material that stains positive using the periodic acid-Schiff method and
CC is derived from surfactant phospholipids and protein components.
CC Excessive lipoproteins accumulation in the alveoli results in severe
CC respiratory distress. {ECO:0000269|PubMed:7491219}. Note=The disease is
CC caused by variants affecting the gene represented in this entry.
CC -!- DISEASE: Respiratory distress syndrome in premature infants (RDS)
CC [MIM:267450]: A lung disease affecting usually premature newborn
CC infants. It is characterized by deficient gas exchange, diffuse
CC atelectasis, high-permeability lung edema and fibrin-rich alveolar
CC deposits called 'hyaline membranes'. {ECO:0000269|PubMed:11063734}.
CC Note=Disease susceptibility may be associated with variants affecting
CC the gene represented in this entry. A variation Ile to Thr at position
CC 131 influences the association between specific alleles of SFTPA1 and
CC respiratory distress syndrome in premature infants.
CC -!- MISCELLANEOUS: Pulmonary surfactant consists of 90% lipid and 10%
CC protein. There are 4 surfactant-associated proteins: 2 collagenous,
CC carbohydrate-binding glycoproteins (SP-A and SP-D) and 2 small
CC hydrophobic proteins (SP-B and SP-C).
CC -!- SEQUENCE CAUTION:
CC Sequence=AAA88099.1; Type=Erroneous initiation; Evidence={ECO:0000305};
CC -!- WEB RESOURCE: Name=SeattleSNPs;
CC URL="http://pga.gs.washington.edu/data/sftpb/";
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DR EMBL; J02761; AAA60212.1; -; mRNA.
DR EMBL; M24461; AAB59541.1; -; Genomic_DNA.
DR EMBL; AF400074; AAK77913.1; -; Genomic_DNA.
DR EMBL; BC032785; AAH32785.1; -; mRNA.
DR EMBL; M16764; AAA88099.1; ALT_INIT; mRNA.
DR EMBL; M19097; AAA36628.1; -; mRNA.
DR CCDS; CCDS1983.2; -.
DR PIR; A31361; LNHUB.
DR RefSeq; NP_000533.3; NM_000542.3.
DR RefSeq; NP_942140.2; NM_198843.2.
DR PDB; 1DFW; IR; -; A=201-225.
DR PDB; 1KMR; NMR; -; A=211-225.
DR PDB; 1RG3; NMR; -; A=263-278.
DR PDB; 1RG4; NMR; -; A=263-278.
DR PDB; 1SSZ; IR; -; A=208-278.
DR PDB; 2DWF; NMR; -; A=208-278.
DR PDB; 2JOU; NMR; -; A=208-278.
DR PDB; 2M0H; NMR; -; A=259-280.
DR PDB; 2M1T; NMR; -; A=259-278.
DR PDBsum; 1DFW; -.
DR PDBsum; 1KMR; -.
DR PDBsum; 1RG3; -.
DR PDBsum; 1RG4; -.
DR PDBsum; 1SSZ; -.
DR PDBsum; 2DWF; -.
DR PDBsum; 2JOU; -.
DR PDBsum; 2M0H; -.
DR PDBsum; 2M1T; -.
DR AlphaFoldDB; P07988; -.
DR BMRB; P07988; -.
DR PCDDB; P07988; -.
DR SMR; P07988; -.
DR BioGRID; 112337; 2.
DR IntAct; P07988; 1.
DR STRING; 9606.ENSP00000386346; -.
DR GlyGen; P07988; 2 sites.
DR PhosphoSitePlus; P07988; -.
DR BioMuta; SFTPB; -.
DR DMDM; 131418; -.
DR MassIVE; P07988; -.
DR PaxDb; P07988; -.
DR PeptideAtlas; P07988; -.
DR PRIDE; P07988; -.
DR ProteomicsDB; 52054; -.
DR Antibodypedia; 31946; 361 antibodies from 31 providers.
DR DNASU; 6439; -.
DR Ensembl; ENST00000393822.7; ENSP00000377409.4; ENSG00000168878.19.
DR Ensembl; ENST00000409383.6; ENSP00000386346.2; ENSG00000168878.19.
DR Ensembl; ENST00000519937.7; ENSP00000428719.2; ENSG00000168878.19.
DR GeneID; 6439; -.
DR KEGG; hsa:6439; -.
DR MANE-Select; ENST00000519937.7; ENSP00000428719.2; NM_000542.5; NP_000533.4.
DR UCSC; uc061lja.1; human.
DR CTD; 6439; -.
DR DisGeNET; 6439; -.
DR GeneCards; SFTPB; -.
DR HGNC; HGNC:10801; SFTPB.
DR HPA; ENSG00000168878; Tissue enriched (lung).
DR MalaCards; SFTPB; -.
DR MIM; 178640; gene.
DR MIM; 265120; phenotype.
DR MIM; 267450; phenotype.
DR neXtProt; NX_P07988; -.
DR OpenTargets; ENSG00000168878; -.
DR Orphanet; 70587; Infant acute respiratory distress syndrome.
DR Orphanet; 217563; Neonatal acute respiratory distress due to SP-B deficiency.
DR PharmGKB; PA35713; -.
DR VEuPathDB; HostDB:ENSG00000168878; -.
DR eggNOG; KOG1340; Eukaryota.
DR GeneTree; ENSGT00940000161711; -.
DR InParanoid; P07988; -.
DR OMA; APHTICS; -.
DR OrthoDB; 865505at2759; -.
DR PhylomeDB; P07988; -.
DR PathwayCommons; P07988; -.
DR Reactome; R-HSA-5683826; Surfactant metabolism.
DR Reactome; R-HSA-5688031; Defective pro-SFTPB causes SMDP1 and RDS.
DR Reactome; R-HSA-5688849; Defective CSF2RB causes SMDP5.
DR Reactome; R-HSA-5688890; Defective CSF2RA causes SMDP4.
DR SignaLink; P07988; -.
DR SIGNOR; P07988; -.
DR BioGRID-ORCS; 6439; 13 hits in 1065 CRISPR screens.
DR ChiTaRS; SFTPB; human.
DR EvolutionaryTrace; P07988; -.
DR GeneWiki; Pulmonary_surfactant-associated_protein_B; -.
DR GenomeRNAi; 6439; -.
DR Pharos; P07988; Tbio.
DR PRO; PR:P07988; -.
DR Proteomes; UP000005640; Chromosome 2.
DR RNAct; P07988; protein.
DR Bgee; ENSG00000168878; Expressed in lower lobe of lung and 175 other tissues.
DR ExpressionAtlas; P07988; baseline and differential.
DR Genevisible; P07988; HS.
DR GO; GO:0097208; C:alveolar lamellar body; IBA:GO_Central.
DR GO; GO:0045334; C:clathrin-coated endocytic vesicle; TAS:Reactome.
DR GO; GO:0005789; C:endoplasmic reticulum membrane; TAS:Reactome.
DR GO; GO:0005576; C:extracellular region; TAS:Reactome.
DR GO; GO:0005615; C:extracellular space; IBA:GO_Central.
DR GO; GO:0042599; C:lamellar body; TAS:Reactome.
DR GO; GO:0005764; C:lysosome; IEA:InterPro.
DR GO; GO:0005771; C:multivesicular body; IBA:GO_Central.
DR GO; GO:0097486; C:multivesicular body lumen; TAS:Reactome.
DR GO; GO:0009887; P:animal organ morphogenesis; TAS:ProtInc.
DR GO; GO:0007585; P:respiratory gaseous exchange by respiratory system; TAS:ProtInc.
DR GO; GO:0006665; P:sphingolipid metabolic process; IEA:InterPro.
DR InterPro; IPR003119; SAP_A.
DR InterPro; IPR007856; SapB_1.
DR InterPro; IPR008138; SapB_2.
DR InterPro; IPR008373; Saposin.
DR InterPro; IPR011001; Saposin-like.
DR InterPro; IPR008139; SaposinB_dom.
DR Pfam; PF02199; SapA; 1.
DR Pfam; PF05184; SapB_1; 1.
DR Pfam; PF03489; SapB_2; 2.
DR PRINTS; PR01797; SAPOSIN.
DR SMART; SM00162; SAPA; 1.
DR SMART; SM00741; SapB; 3.
DR SUPFAM; SSF47862; SSF47862; 3.
DR PROSITE; PS51110; SAP_A; 1.
DR PROSITE; PS50015; SAP_B; 3.
PE 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Disease variant; Disulfide bond;
KW Gaseous exchange; Glycoprotein; Reference proteome; Repeat; Secreted;
KW Signal; Surface film.
FT SIGNAL 1..24
FT /evidence="ECO:0000255"
FT PROPEP 25..200
FT /id="PRO_0000031647"
FT CHAIN 201..279
FT /note="Pulmonary surfactant-associated protein B"
FT /id="PRO_0000031648"
FT PROPEP 280..381
FT /id="PRO_0000031649"
FT DOMAIN 25..65
FT /note="Saposin A-type"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00414"
FT DOMAIN 65..147
FT /note="Saposin B-type 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DOMAIN 204..281
FT /note="Saposin B-type 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DOMAIN 295..370
FT /note="Saposin B-type 3"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT CARBOHYD 129
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT CARBOHYD 311
FT /note="N-linked (GlcNAc...) asparagine"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 69..143
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 72..137
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 100..112
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 208..277
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415,
FT ECO:0000269|PubMed:1568474"
FT DISULFID 211..271
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415,
FT ECO:0000269|PubMed:1568474"
FT DISULFID 235..246
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415,
FT ECO:0000269|PubMed:1568474"
FT DISULFID 248
FT /note="Interchain"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415,
FT ECO:0000269|PubMed:1568474"
FT DISULFID 299..366
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 302..360
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT DISULFID 325..335
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00415"
FT VARIANT 131
FT /note="T -> I (in dbSNP:rs1130866)"
FT /evidence="ECO:0000269|PubMed:11076040, ECO:0000269|Ref.3"
FT /id="VAR_006948"
FT VARIANT 176
FT /note="L -> F (in dbSNP:rs3024801)"
FT /evidence="ECO:0000269|Ref.3"
FT /id="VAR_013099"
FT VARIANT 228
FT /note="A -> I (requires 2 nucleotide substitutions)"
FT /evidence="ECO:0000269|PubMed:1568474"
FT /id="VAR_006950"
FT VARIANT 228
FT /note="A -> R (requires 2 nucleotide substitutions)"
FT /evidence="ECO:0000269|PubMed:2924687,
FT ECO:0000269|PubMed:3035561"
FT /id="VAR_006949"
FT VARIANT 236
FT /note="R -> C (in SMDP1; dbSNP:rs137853202)"
FT /evidence="ECO:0000269|PubMed:7491219"
FT /id="VAR_036856"
FT VARIANT 272
FT /note="R -> H (in dbSNP:rs3024809)"
FT /evidence="ECO:0000269|Ref.3"
FT /id="VAR_013100"
FT CONFLICT 178
FT /note="L -> V (in Ref. 6; AAA36628)"
FT /evidence="ECO:0000305"
FT CONFLICT 318
FT /note="P -> L (in Ref. 5; AAA88099)"
FT /evidence="ECO:0000305"
FT HELIX 213..221
FT /evidence="ECO:0007829|PDB:1KMR"
FT HELIX 260..263
FT /evidence="ECO:0007829|PDB:2M0H"
FT STRAND 265..268
FT /evidence="ECO:0007829|PDB:1RG3"
FT HELIX 269..276
FT /evidence="ECO:0007829|PDB:1RG3"
SQ SEQUENCE 381 AA; 42117 MW; 9FD7F66678A35153 CRC64;
MAESHLLQWL LLLLPTLCGP GTAAWTTSSL ACAQGPEFWC QSLEQALQCR ALGHCLQEVW
GHVGADDLCQ ECEDIVHILN KMAKEAIFQD TMRKFLEQEC NVLPLKLLMP QCNQVLDDYF
PLVIDYFQNQ TDSNGICMHL GLCKSRQPEP EQEPGMSDPL PKPLRDPLPD PLLDKLVLPV
LPGALQARPG PHTQDLSEQQ FPIPLPYCWL CRALIKRIQA MIPKGALAVA VAQVCRVVPL
VAGGICQCLA ERYSVILLDT LLGRMLPQLV CRLVLRCSMD DSAGPRSPTG EWLPRDSECH
LCMSVTTQAG NSSEQAIPQA MLQACVGSWL DREKCKQFVE QHTPQLLTLV PRGWDAHTTC
QALGVCGTMS SPLQCIHSPD L
