Seroatlas · Human Serome Atlas

LACTB

Serine beta-lactamase-like protein LACTB, mitochondrial

Also known as: FLJ14902, LACTB_HUMAN, MRPL56

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

Protein identityUniProt · HPA

UniProt accession: P83111
Gene: LACTB
Ensembl: ENSG00000103642
Chromosome: 15
Canonical length: 547 aa
Protein class: Enzymes, Predicted intracellular proteins
Subcellular location: Mitochondria

OverviewNCBI Gene

This gene encodes a mitochondrially-localized protein that has sequence similarity to prokaryotic beta-lactamases. Many of the residues responsible for beta-lactamase activity are not conserved in this protein, suggesting it may have a different enzymatic function. Increased expression of the related mouse gene was found to be associated with obesity. Alternative splicing results in multiple transcript variants encoding different protein isoforms. [provided by RefSeq, Dec 2013]

Canonical amino-acid sequenceUniProt

547 residues, UniProt reviewed canonical sequence.

>P83111|LACTB
     1  MYRLMSAVTA RAAAPGGLAS SCGRRGVHQR AGLPPLGHGW VGGLGLGLGL ALGVKLAGGL
    61  RGAAPAQSPA APDPEASPLA EPPQEQSLAP WSPQTPAPPC SRCFARAIES SRDLLHRIKD
   121  EVGAPGIVVG VSVDGKEVWS EGLGYADVEN RVPCKPETVM RIASISKSLT MVALAKLWEA
   181  GKLDLDIPVQ HYVPEFPEKE YEGEKVSVTT RLLISHLSGI RHYEKDIKKV KEEKAYKALK
   241  MMKENVAFEQ EKEGKSNEKN DFTKFKTEQE NEAKCRNSKP GKKKNDFEQG ELYLREKFEN
   301  SIESLRLFKN DPLFFKPGSQ FLYSTFGYTL LAAIVERASG CKYLDYMQKI FHDLDMLTTV
   361  QEENEPVIYN RARFYVYNKK KRLVNTPYVD NSYKWAGGGF LSTVGDLLKF GNAMLYGYQV
   421  GLFKNSNENL LPGYLKPETM VMMWTPVPNT EMSWDKEGKY AMAWGVVERK QTYGSCRKQR
   481  HYASHTGGAV GASSVLLVLP EELDTETINN KVPPRGIIVS IICNMQSVGL NSTALKIALE
   541  FDKDRSD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against LACTB 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: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.36
Highest tissue expression: 54 nTPM

Expression across tissuesHPA

Tissue

bone marrow: 54 nTPM
skeletal muscle: 48 nTPM
liver: 40 nTPM
tongue: 34 nTPM
adrenal gland: 24 nTPM
kidney: 22 nTPM

Single-cell type

neutrophils: 184 nCPM
monocytes: 153 nCPM
late primary spermatocytes: 152 nCPM
mast cells: 129 nCPM
kupffer cells: 102 nCPM
macrophages: 99 nCPM

Immune cell

myeloid DC: 9.8 nTPM
classical monocyte: 8.4 nTPM
intermediate monocyte: 8.3 nTPM
non-classical monocyte: 7.3 nTPM
neutrophil: 5.3 nTPM
eosinophil: 4.5 nTPM

Brain region

choroid plexus: 19 nTPM
thalamus: 14 nTPM
white matter: 14 nTPM
pons: 12 nTPM
hypothalamus: 12 nTPM
medulla oblongata: 12 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about LACTB.

Disease | GeneticClinVar

1 pathogenic / likely-pathogenic of 87 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

Hypercholesterolemia, familial, 1

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): 0.99
gnomAD pLI: 0
gnomAD missense Z: 1.26
DepMap mean gene effect: -0.28
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

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

LACTB is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

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

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