Lipocalin-1 is a protein that in humans is encoded by the LCN1 gene.[3][4]

LCN1
Available structures
PDBHuman UniProt search: PDBe RCSB
Identifiers
AliasesLCN1, PMFA, TLC, TP, VEGP, lipocalin 1
External IDsOMIM: 151675; HomoloGene: 48099; GeneCards: LCN1; OMA:LCN1 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001252617
NM_001252618
NM_001252619
NM_002297

n/a

RefSeq (protein)

n/a

Location (UCSC)Chr 9: 135.52 – 135.53 Mbn/a
PubMed search[2]n/a
Wikidata
View/Edit Human

The protein encoded by this gene belongs to the lipocalin family. Lipocalins are a group of extracellular proteins that are able to bind lipophiles by enclosure within their structures to minimize solvent contact. This protein may bind hydrophobic ligands and inhibit cysteine proteinases. It may also play a role in taste reception.[4]

Structure

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NMR Structure of LCN1

Proteins are classified into the lipocalin family by their 8 antiparallel beta-sheets that form a barrel structure which acts as the binding site for ligands.

Function

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Lipocalin-1 (LCN1) is capable of binding a wide variety of lipophilic molecules along with zinc and chloride ions. Because of this feature, LCN1’s main function is thought to be the removal of potentially harmful lipids and lipophilic molecules from the body by binding them. The LCN1-Ligand complex is then imported via Lipocalin-1-Interacting Membrane Receptor (LIMR) so the bound molecule can be broken down safely within the cell.[5] This process of retrieving molecules may impact several processes including pheromone signaling, immunodulation, inflammation, detoxification, tissue development, apoptosis and more.

LCN1 shares three sequence motifs with cystatins which enables LCN1 to act in a similar manner to cystatins as a cysteine proteinase inhibitor. These domains have specifically been shown to bind Papain.[6][7]

LCN1 also plays a role in stabilizing the lipid layer of the tear film, though the details of this are not yet well understood.[8][9]

History

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Lipocalin-1 was initially thought to be produced exclusively by exocrine glands but has also been found in corticotrophs of the pituitary gland.[10]

Alternate Names: Human Tear Prealbumin, Tear Lipocalin, von Ebner’s Gland Protein

Clinical

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When a cell is under stress, due to inflammation, infection, or otherwise, it will produce elevated levels of lipocalin-1 (LCN1). This makes it a potential noninvasive biomarker for various diseases. This potential has been shown in a study of IVF blastocysts, where elevated levels of LCN1 indicated aneuploidy in the blastocyst.[11]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000160349Ensembl, May 2017
  2. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  3. ^ Lassagne H, Ressot C, Mattei MG, Gachon AM (October 1993). "Assignment of the human tear lipocalin gene (LCN1) to 9q34 by in situ hybridization". Genomics. 18 (1): 160–1. doi:10.1006/geno.1993.1444. PMID 8276406.
  4. ^ a b "Entrez Gene: LCN1 lipocalin 1 (tear prealbumin)".
  5. ^ Wojnar P, Lechner M, Redl B (May 2003). "Antisense down-regulation of lipocalin-interacting membrane receptor expression inhibits cellular internalization of lipocalin-1 in human NT2 cells". The Journal of Biological Chemistry. 278 (18): 16209–15. doi:10.1074/jbc.M210922200. PMID 12591932. S2CID 24433456.
  6. ^ van't Hof W, Blankenvoorde MF, Veerman EC, Amerongen AV (January 1997). "The salivary lipocalin von Ebner's gland protein is a cysteine proteinase inhibitor". The Journal of Biological Chemistry. 272 (3): 1837–41. doi:10.1074/jbc.272.3.1837. PMID 8999869. S2CID 2650128.
  7. ^ Wojnar P, van't Hof W, Merschak P, Lechner M, Redl B (October 2001). "The N-terminal part of recombinant human tear lipocalin/von Ebner's gland protein confers cysteine proteinase inhibition depending on the presence of the entire cystatin-like sequence motifs". Biological Chemistry. 382 (10): 1515–20. doi:10.1515/BC.2001.186. PMID 11727836. S2CID 44411516.
  8. ^ Nagyová B, Tiffany JM (July 1999). "Components responsible for the surface tension of human tears". Current Eye Research. 19 (1): 4–11. doi:10.1076/ceyr.19.1.4.5341. PMID 10415451.
  9. ^ Saaren-Seppälä H, Jauhiainen M, Tervo TM, Redl B, Kinnunen PK, Holopainen JM (October 2005). "Interaction of purified tear lipocalin with lipid membranes". Investigative Ophthalmology & Visual Science. 46 (10): 3649–56. doi:10.1167/iovs.05-0176. PMID 16186346.
  10. ^ Wojnar P, Dirnhofer S, Ladurner P, Berger P, Redl B (March 2002). "Human lipocalin-1, a physiological scavenger of lipophilic compounds, is produced by corticotrophs of the pituitary gland". The Journal of Histochemistry and Cytochemistry. 50 (3): 433–5. doi:10.1177/002215540205000314. PMID 11850445. S2CID 26078329.
  11. ^ McReynolds S, Vanderlinden L, Stevens J, Hansen K, Schoolcraft WB, Katz-Jaffe MG (June 2011). "Lipocalin-1: a potential marker for noninvasive aneuploidy screening". Fertility and Sterility. 95 (8): 2631–3. doi:10.1016/j.fertnstert.2011.01.141. PMID 21324447.

Further reading

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