Seroatlas · Human Serome Atlas

ALPP

Alkaline phosphatase, placental type

Also known as: PALP, PLAP, PPB1_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P05187
Gene
ALPP
Ensembl
ENSG00000163283
Chromosome
2
Canonical length
535 aa
Protein class
Cancer-related genes, Enzymes, Metabolic proteins, Plasma proteins, Predicted intracellular proteins
Subcellular location
Plasma membrane
Secretome location
Intracellular and membrane
Quaternary structure
Homodimer

OverviewNCBI Gene

The protein encoded by this gene is an alkaline phosphatase, a metalloenzyme that catalyzes the hydrolysis of phosphoric acid monoesters. It belongs to a multigene family composed of four alkaline phosphatase isoenzymes. The enzyme functions as a homodimer and has a catalytic site containing one magnesium and two zinc ions, which are required for its enzymatic function. One of the main sources of this enzyme is the liver, and thus, it's one of several indicators of liver injury in different clinical conditions. In pregnant women, this protein is primarily expressed in placental and endometrial tissue, however, strong ectopic expression has been detected in ovarian adenocarcinoma, serous cystadenocarcinoma, and other ovarian cancer cells. [provided by RefSeq, Aug 2020]

Canonical amino-acid sequenceUniProt

535 residues, UniProt reviewed canonical sequence.

>P05187|ALPP
     1  MLGPCMLLLL LLLGLRLQLS LGIIPVEEEN PDFWNREAAE ALGAAKKLQP AQTAAKNLII
    61  FLGDGMGVST VTAARILKGQ KKDKLGPEIP LAMDRFPYVA LSKTYNVDKH VPDSGATATA
   121  YLCGVKGNFQ TIGLSAAARF NQCNTTRGNE VISVMNRAKK AGKSVGVVTT TRVQHASPAG
   181  TYAHTVNRNW YSDADVPASA RQEGCQDIAT QLISNMDIDV ILGGGRKYMF RMGTPDPEYP
   241  DDYSQGGTRL DGKNLVQEWL AKRQGARYVW NRTELMQASL DPSVTHLMGL FEPGDMKYEI
   301  HRDSTLDPSL MEMTEAALRL LSRNPRGFFL FVEGGRIDHG HHESRAYRAL TETIMFDDAI
   361  ERAGQLTSEE DTLSLVTADH SHVFSFGGYP LRGSSIFGLA PGKARDRKAY TVLLYGNGPG
   421  YVLKDGARPD VTESESGSPE YRQQSAVPLD EETHAGEDVA VFARGPQAHL VHGVQEQTFI
   481  AHVMAFAACL EPYTACDLAP PAGTTDAAHP GRSVVPALLP LLAGTLLLLE TATAP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against ALPP can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.26
Highest tissue expression
33 nTPM

Expression across tissuesHPA

Tissue

  • placenta: 33 nTPM
  • cervix: 17 nTPM
  • lung: 4.2 nTPM
  • fallopian tube: 1.5 nTPM
  • endometrium: 0.2 nTPM
  • cerebral cortex: 0.1 nTPM

Single-cell type

  • endometrial secretory cells: 75 nCPM
  • alveolar cells type 1: 68 nCPM
  • transitional alveolar cells: 21 nCPM
  • endometrial luminal cells: 8.5 nCPM
  • syncytiotrophoblasts: 7.7 nCPM
  • migrating cytotrophoblasts: 3 nCPM

Immune cell

  • basophil: 0.1 nTPM
  • neutrophil: 0.1 nTPM
  • NK-cell: 0.1 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM

Brain region

  • cerebral cortex: 1 nTPM
  • cerebellum: 0.9 nTPM
  • medulla oblongata: 0.8 nTPM
  • pons: 0.8 nTPM
  • white matter: 0.8 nTPM
  • amygdala: 0.7 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.3
gnomAD pLI
0
gnomAD missense Z
-0.45
DepMap mean gene effect
0.13
DepMap dependency class
none

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads ALPP as an antibody target. Whether an autoantibody or antibody against ALPP could matter depends on whether native ALPP is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

ALPP is annotated at the cell surface, where native ALPP is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label ALPP as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/ALPP. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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