LTF P02788

乳转铁蛋白 (乳铁蛋白) (EC 3.4.21.-) (生长抑制蛋白12) (塔拉乳铁蛋白) [裂解为: 乳铁蛋白肽-H (Lfcin-H); Kaliocin-1; Lactoferroxin-A; Lactoferroxin-B; Lactoferroxin-C]

功能描述

转铁蛋白是铁结合转运蛋白，通常在结合阴离子（通常是碳酸氢盐）的同时结合两个Fe(3+)离子。 {ECO:0000269|PubMed:22900286}.; FUNCTION: [乳铁蛋白]: 主要的铁结合和多功能蛋白，存在于外分泌液如母乳和粘膜分泌物中 (PubMed:11179314, PubMed:12693969, PubMed:14573629, PubMed:1599934, PubMed:3169987, PubMed:6802759)。具有抗菌活性，该活性依赖于细胞外阳离子浓度 (PubMed:6802759)。抗菌特性包括抑菌作用，这与其螯合游离铁从而抑制微生物生长的能力有关，以及导致细菌外膜脂多糖释放的直接杀菌特性 (PubMed:11179314, PubMed:12693969, PubMed:14573629, PubMed:1599934, PubMed:3169987, PubMed:6802759)。还能抑制铜绿假单胞菌感染中的细菌生物膜形成 (PubMed:12037568)。对白色念珠菌具有较弱的抗真菌活性 (PubMed:11083624)。对成骨细胞具有合成代谢、分化和抗凋亡作用，还能抑制破骨细胞生成，可能在调节骨生长中发挥作用 (PubMed:15166119)。促进C型腺病毒与上皮细胞的结合，促进腺病毒感染 (PubMed:17079302)。能抑制乳头瘤病毒感染 (PubMed:17481742)。刺激TLR4信号通路导致NF-kappa-B激活和随后的促炎细胞因子产生，同时也干扰脂多糖(LPS)刺激的TLR4信号传导 (PubMed:20345905)。当由凋亡细胞分泌时，抑制中性粒细胞向凋亡部位的迁移 (PubMed:19033648)。刺激VEGFA介导的内皮细胞迁移和增殖 (PubMed:16842782)。结合肝素、硫酸软骨素以及可能的其它糖胺聚糖(GAGs) (PubMed:9359845)。还特异性结合肺炎球菌表面蛋白A (PspA)、细菌脂多糖(LPS)的脂质A部分、溶菌酶和DNA (PubMed:9359845)。 {ECO:0000269|PubMed:11083624, ECO:0000269|PubMed:11179314, ECO:0000269|PubMed:12037568, ECO:0000269|PubMed:12693969, ECO:0000269|PubMed:14573629, ECO:0000269|PubMed:15166119, ECO:0000269|PubMed:1599934, ECO:0000269|PubMed:16842782, ECO:0000269|PubMed:17079302, ECO:0000269|PubMed:17481742, ECO:0000269|PubMed:19033648, ECO:0000269|PubMed:20345905, ECO:0000269|PubMed:3169987, ECO:0000269|PubMed:6802759, ECO:0000269|PubMed:9359845}.; FUNCTION: 乳铁蛋白肽结合细菌表面，对杀菌功能至关重要。对乳头瘤病毒感染具有一定的抗病毒活性 (PubMed:17481742)。N端区域显示对白色念珠菌有强抗真菌活性 (PubMed:11083624)。包含两个BBXB肝素结合共有序列，似乎形成主要的功能性GAG结合位点。 {ECO:0000269|PubMed:11083624, ECO:0000269|PubMed:17481742}.; FUNCTION: [Kaliocin-1]: 具有抗菌活性，能够使不同的离子透过脂质体膜。 {ECO:0000269|PubMed:12693969}.; FUNCTION: [Lactoferroxin-A]: 具有阿片受体拮抗活性 (PubMed:1369293)。对mu-受体显示偏好性 (PubMed:1369293)。 {ECO:0000269|PubMed:1369293}.; FUNCTION: [Lactoferroxin-B]: 具有阿片受体拮抗活性 (PubMed:1369293)。对kappa-受体的偏好程度高于mu-受体 (PubMed:1369293)。 {ECO:0000269|PubMed:1369293}.; FUNCTION: [Lactoferroxin-C]: 具有阿片受体拮抗活性 (PubMed:1369293)。对kappa-受体的偏好程度高于mu-受体 (PubMed:1369293)。 {ECO:0000269|PubMed:1369293}.; FUNCTION: 乳铁蛋白转铁蛋白样结构域1作为肽酶S60家族的丝氨酸蛋白酶发挥作用，切割富含精氨酸的区域 (PubMed:12535064)。此功能有助于抗菌活性 (PubMed:12535064)。显示优先切割-Arg-Ser-Arg-Arg-|-和-Arg-Arg-Ser-Arg-|-位点，以及Z-Phe-Arg-|-氨基甲基香豆素位点 (PubMed:12535064)。 {ECO:0000269|PubMed:12535064}.; FUNCTION: [Isoform DeltaLf]: 具有抗增殖特性和诱导细胞周期停滞能力的转录因子 (PubMed:15222485)。结合在SKP1、BAX、DCPS和SELENOH启动子中发现的DeltaLf反应元件 (PubMed:22320386)。 {ECO:0000269|PubMed:15222485, ECO:0000269|PubMed:22320386}.

组织特异性

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.

亚细胞定位

[Isoform 1]: Secreted. Cytoplasmic granule. Note=Secreted into most exocrine fluids by various endothelial cells. Stored in the secondary granules of neutrophils.; SUBCELLULAR LOCATION: [Isoform DeltaLf]: Cytoplasm. Nucleus. Note=Mainly localized in the cytoplasm.