LTF
GeneName
LTF
Summary
Lactoferrin, also known as LTF, is a multifunctional glycoprotein with a mass of 78 kDa, primarily expressed in secretory granules of neutrophils and in various tissues including the mucosal surfaces. It is involved in several biological processes such as the antibacterial and antifungal humoral responses, iron ion transport, and the regulation of immune responses. Lactoferrin exhibits a range of molecular functions including iron ion binding, DNA binding, and serine-type endopeptidase activity. It is found in various cellular compartments including the extracellular space, cytoplasm, and cell surface, and plays a role in mucosal immunity and inflammation.
Importance
Lactoferrin is relevant to: - The innate immune response, particularly in mucosal tissues, due to its antimicrobial properties and ability to sequester iron, limiting bacterial growth. - Bone health and development, as it positively regulates osteoblast differentiation and bone mineralization. - The modulation of inflammatory processes, given its role in regulating cytokine production and immune cell activity. - Viral infections, through its negative regulation of viral processes and genome replication.
Top Products
For researchers investigating LTF, we recommend two excellent primary antibodies. The first is the well-cited polyclonal antibody, Anti-Lactoferrin antibody (ab15811), which has garnered 22 citations, highlighting its reliability in Western blotting (WB). Additionally, we offer the recombinant antibody, Anti-Lactoferrin antibody [EPR4337] (ab109216), which is suitable for both WB and immunocytochemistry (ICC). This recombinant option ensures batch-to-batch consistency, making it an ideal choice for those requiring dependable results in their experiments. The Human Lactoferrin Autoantibody ELISA Kit (ab284010) is an excellent option for researchers looking to measure lactoferrin autoantibodies in their samples.
Abcam Product Citation Summary
The data indicates that the LTF antibody (ab200015) has been utilised in studies focusing on acute osteomyelitis and human amniotic fluid. This suggests its relevance in both infectious disease contexts and developmental biology.
Abcam Product Citation Table
Function
Transferrins are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate.
Lactotransferrin
Major iron-binding and multifunctional protein found in exocrine fluids such as breast milk and mucosal secretions (PubMed:11179314, PubMed:12693969, PubMed:14573629, PubMed:1599934, PubMed:3169987, PubMed:6802759). Has antimicrobial activity, which depends on the extracellular cation concentration (PubMed:6802759). Antimicrobial properties include bacteriostasis, which is related to its ability to sequester free iron and thus inhibit microbial growth, as well as direct bactericidal properties leading to the release of lipopolysaccharides from the bacterial outer membrane (PubMed:11179314, PubMed:12693969, PubMed:14573629, PubMed:1599934, PubMed:3169987, PubMed:6802759). Can also prevent bacterial biofilm development in P.aeruginosa infection (PubMed:12037568). Has weak antifungal activity against C.albicans (PubMed:11083624). Has anabolic, differentiating and anti-apoptotic effects on osteoblasts and can also inhibit osteoclastogenesis, possibly playing a role in the regulation of bone growth (PubMed:15166119). Promotes binding of species C adenoviruses to epithelial cells, promoting adenovirus infection (PubMed:17079302). Can inhibit papillomavirus infections (PubMed:17481742). Stimulates the TLR4 signaling pathway leading to NF-kappa-B activation and subsequent pro-inflammatory cytokine production while also interfering with the lipopolysaccharide (LPS)-stimulated TLR4 signaling (PubMed:20345905). Inhibits neutrophil granulocyte migration to sites of apoptosis, when secreted by apoptotic cells (PubMed:19033648). Stimulates VEGFA-mediated endothelial cell migration and proliferation (PubMed:16842782). Binds heparin, chondroitin sulfate and possibly other glycosaminoglycans (GAGs) (PubMed:9359845). Also binds specifically to pneumococcal surface protein A (PspA), the lipid A portion of bacterial lipopolysaccharide (LPS), lysozyme and DNA (PubMed:9359845).
Lactoferricin binds to the bacterial surface and is crucial for the bactericidal functions. Has some antiviral activity against papillomavirus infection (PubMed:17481742). N-terminal region shows strong antifungal activity against C.albicans (PubMed:11083624). Contains two BBXB heparin-binding consensus sequences that appear to form the predominate functional GAG-binding site.
Kaliocin-1
Has antimicrobial activity and is able to permeabilize different ions through liposomal membranes.
Lactoferroxin-A
Has opioid antagonist activity (PubMed:1369293). Shows preference for mu-receptor (PubMed:1369293).
Lactoferroxin-B
Has opioid antagonist activity (PubMed:1369293). Shows higher degrees of preference for kappa-receptors than for mu-receptors (PubMed:1369293).
Lactoferroxin-C
Has opioid antagonist activity (PubMed:1369293). Shows higher degrees of preference for kappa-receptors than for mu-receptors (PubMed:1369293).
The lactotransferrin transferrin-like domain 1 functions as a serine protease of the peptidase S60 family that cuts arginine rich regions (PubMed:12535064). This function contributes to the antimicrobial activity (PubMed:12535064). Shows a preferential cleavage at -Arg-Ser-Arg-Arg-|- and -Arg-Arg-Ser-Arg-|-, and of Z-Phe-Arg-|-aminomethylcoumarin sites (PubMed:12535064).
Isoform DeltaLf
Transcription factor with antiproliferative properties and ability to induce cell cycle arrest (PubMed:15222485). Binds to the DeltaLf response element found in the SKP1, BAX, DCPS, and SELENOH promoters (PubMed:22320386).
Post-translational modifications
Isoform DeltaLf
Phosphorylation at Ser-10 activates the transcriptional activity (PubMed:20404350). Phosphorylation at Ser-10 also promotes proteasomal degradation (PubMed:20404350). Alternatively can undergo O-GlcNAcylation at Ser-10 (PubMed:20404350).
Isoform DeltaLf
O-GlcNAcylation at Ser-10 inhibits DNA binding and negatively regulates the transcriptional activity (PubMed:20404350). Alternatively can undergo phosphorylation at Ser-10 (PubMed:20404350).
Poly-N-acetyllactosaminic carbohydrate moiety seems to be needed for TLR4 activation.
Sequence Similarities
Belongs to the transferrin family.
Tissue Specificity
High levels are found in saliva and tears, intermediate levels in serum and plasma, and low levels in urine. In kidney, detected in the distal collecting tubules in the medulla but not in the cortical region or in blood vessels. Detected in peripheral blood neutrophils (at protein level). Isoform 1 and isoform DeltaLf are expressed in breast, prostate, spleen, pancreas, kidney, small intestine, lung, skeletal muscle, uterus, thymus and fetal liver. Isoform 1 is expressed in brain, testis and peripheral blood leukocytes; isoform DeltaLf is barely detectable in these tissues. Isoform DeltaLf is expressed in placenta, liver and ovary; isoform 1 is barely detectable in these tissues. In kidney, isoform 1 is expressed at high levels in the collecting tubules of the medulla but at very low levels in the cortex.
Cellular localization
- Isoform 1
- Secreted
- Cytoplasmic granule
- Secreted into most exocrine fluids by various endothelial cells. Stored in the secondary granules of neutrophils.
- Isoform DeltaLf
- Cytoplasm
- Nucleus
- Mainly localized in the cytoplasm.
Alternative names
GIG12, LF, LTF, Lactotransferrin, Lactoferrin, Growth-inhibiting protein 12, Talalactoferrin