Search Results

Overview

Uniprot IDP21741
Protein NameMidkine
Gene NameMDK
OrganismHomo sapiens

Kla Sites from experimental identification

Position Flanking peptide
124 QETIRVTKPCTPKTK
87 FGADCKYKFENWGAC

Function

Secreted protein that functions as a cytokine and growth factor and mediates its signal through cell-surface proteoglycan and non-proteoglycan receptors (PubMed:10212223, PubMed:10772929, PubMed:12084985, PubMed:12122009, PubMed:12573468, PubMed:15466886, PubMed:18469519, PubMed:24458438). Binds cell-surface proteoglycan receptors via their chondroitin sulfate (CS) groups (PubMed:10212223, PubMed:12084985). Thereby regulates many processes like inflammatory response, cell proliferation, cell adhesion, cell growth, cell survival, tissue regeneration, cell differentiation and cell migration (PubMed:10212223, PubMed:10683378, PubMed:10772929, PubMed:12084985, PubMed:12122009, PubMed:12573468, PubMed:15466886, PubMed:22323540, PubMed:24458438). Participates in inflammatory processes by exerting two different activities. Firstly, mediates neutrophils and macrophages recruitment to the sites of inflammation both by direct action by cooperating namely with ITGB2 via LRP1 and by inducing chemokine expression (PubMed:10683378, PubMed:24458438). This inflammation can be accompanied by epithelial cell survival and smooth muscle cell migration after renal and vessel damage, respectively (PubMed:10683378). Secondly, suppresses the development of tolerogenic dendric cells thereby inhibiting the differentiation of regulatory T cells and also promote T cell expansion through NFAT signaling and Th1 cell differentiation (PubMed:22323540). Promotes tissue regeneration after injury or trauma. After heart damage negatively regulates the recruitment of inflammatory cells and mediates cell survival through activation of anti-apoptotic signaling pathways via MAPKs and AKT pathways through the activation of angiogenesis (By similarity). Also facilitates liver regeneration as well as bone repair by recruiting macrophage at trauma site and by promoting cartilage development by facilitating chondrocyte differentiation (By similarity). Plays a role in brain by promoting neural precursor cells survival and growth through interaction with heparan sulfate proteoglycans (By similarity). Binds PTPRZ1 and promotes neuronal migration and embryonic neurons survival (PubMed:10212223). Binds SDC3 or GPC2 and mediates neurite outgrowth and cell adhesion (PubMed:12084985, PubMed:1768439). Binds chondroitin sulfate E and heparin leading to inhibition of neuronal cell adhesion induced by binding with GPC2 (PubMed:12084985). Binds CSPG5 and promotes elongation of oligodendroglial precursor-like cells (By similarity). Also binds ITGA6:ITGB1 complex; this interaction mediates MDK-induced neurite outgrowth (PubMed:15466886, PubMed:1768439). Binds LRP1; promotes neuronal survival (PubMed:10772929). Binds ITGA4:ITGB1 complex; this interaction mediates MDK-induced osteoblast cells migration through PXN phosphorylation (PubMed:15466886). Binds anaplastic lymphoma kinase (ALK) which induces ALK activation and subsequent phosphorylation of the insulin receptor substrate (IRS1), followed by the activation of mitogen-activated protein kinase (MAPK) and PI3-kinase, and the induction of cell proliferation (PubMed:12122009). Promotes epithelial to mesenchymal transition through interaction with NOTCH2 (PubMed:18469519). During arteriogenesis, plays a role in vascular endothelial cell proliferation by inducing VEGFA expression and release which in turn induces nitric oxide synthase expression. Moreover activates vasodilation through nitric oxide synthase activation (By similarity). Negatively regulates bone formation in response to mechanical load by inhibiting Wnt/beta-catenin signaling in osteoblasts (By similarity). In addition plays a role in hippocampal development, working memory, auditory response, early fetal adrenal gland development and the female reproductive system (By similarity)

Protein Sequence

10 MQHRGFLLLT 20 LLALLALTSA 30 VAKKKDKVKK 40 GGPGSECAEW 50 AWGPCTPSSK 60 DCGVGFREGT 70 CGAQTQRIRC 80 RVPCNWKKEF 90 GADCKYKFEN 100 WGACDGGTGT 110 KVRQGTLKKA 120 RYNAQCQETI 130 RVTKPCTPKT 140 KAKAKAKKGK GKD

Gene Ontology

Classification GO ID Description
Cellular Component GO:0042995 cell projection
Biological Process GO:0045893 positive regulation of DNA-templated transcription
Biological Process GO:0010718 positive regulation of epithelial to mesenchymal transition
Biological Process GO:2000347 positive regulation of hepatocyte proliferation
Biological Process GO:0050729 positive regulation of inflammatory response
Biological Process GO:0106016 positive regulation of inflammatory response to wounding
Biological Process GO:0032735 positive regulation of interleukin-12 production
Biological Process GO:0010838 positive regulation of keratinocyte proliferation
Biological Process GO:1904996 positive regulation of leukocyte adhesion to vascular endothelial cell
Biological Process GO:1903039 positive regulation of leukocyte cell-cell adhesion
Biological Process GO:0002690 positive regulation of leukocyte chemotaxis
Biological Process GO:0010759 positive regulation of macrophage chemotaxis
Biological Process GO:2000179 positive regulation of neural precursor cell proliferation
Biological Process GO:2001224 positive regulation of neuron migration
Biological Process GO:0010976 positive regulation of neuron projection development
Biological Process GO:0090023 positive regulation of neutrophil chemotaxis
Biological Process GO:2000391 positive regulation of neutrophil extravasation
Biological Process GO:0048714 positive regulation of oligodendrocyte differentiation
Biological Process GO:0071673 positive regulation of smooth muscle cell chemotaxis
Biological Process GO:1900026 positive regulation of substrate adhesion-dependent cell spreading
Biological Process GO:0045582 positive regulation of T cell differentiation
Biological Process GO:1905564 positive regulation of vascular endothelial cell proliferation
Biological Process GO:0050795 regulation of behavior
Biological Process GO:0046850 regulation of bone remodeling
Biological Process GO:0032330 regulation of chondrocyte differentiation
Biological Process GO:0010996 response to auditory stimulus
Biological Process GO:0051384 response to glucocorticoid
Biological Process GO:0009611 response to wounding
Biological Process GO:0009410 response to xenobiotic stimulus
Biological Process GO:0007614 short-term memory
Biological Process GO:0007165 signal transduction
Biological Process GO:0002286 T cell activation involved in immune response
Biological Process GO:0042246 tissue regeneration
Cellular Component GO:0005576 extracellular region
Molecular Function GO:0035374 chondroitin sulfate binding
Molecular Function GO:0008083 growth factor activity
Molecular Function GO:1904399 heparan sulfate binding
Molecular Function GO:0008201 heparin binding
Biological Process GO:0030325 adrenal gland development
Biological Process GO:0001662 behavioral fear response
Biological Process GO:0030154 cell differentiation
Biological Process GO:0021681 cerebellar granular layer development
Biological Process GO:0021987 cerebral cortex development
Biological Process GO:0007010 cytoskeleton organization
Biological Process GO:0030421 defecation
Biological Process GO:0021542 dentate gyrus development
Biological Process GO:0044849 estrous cycle
Biological Process GO:0106091 glial cell projection elongation
Biological Process GO:0035556 intracellular signal transduction
Biological Process GO:0002232 leukocyte chemotaxis involved in inflammatory response
Biological Process GO:0090090 negative regulation of canonical Wnt signaling pathway
Biological Process GO:0010667 negative regulation of cardiac muscle cell apoptotic process
Biological Process GO:0007162 negative regulation of cell adhesion
Biological Process GO:1904036 negative regulation of epithelial cell apoptotic process
Biological Process GO:0106015 negative regulation of inflammatory response to wounding
Biological Process GO:0043524 negative regulation of neuron apoptotic process
Biological Process GO:0030279 negative regulation of ossification
Biological Process GO:0045590 negative regulation of regulatory T cell differentiation
Biological Process GO:0007399 nervous system development
Biological Process GO:0048477 oogenesis
Biological Process GO:1905653 positive regulation of artery morphogenesis
Biological Process GO:1905555 positive regulation of blood vessel branching
Biological Process GO:0061036 positive regulation of cartilage development
Biological Process GO:0045785 positive regulation of cell adhesion
Biological Process GO:0051781 positive regulation of cell division
Biological Process GO:0030335 positive regulation of cell migration

Reference

[1] Yan M, Tu H, Tang S, Gai Z, Shi Q et al.. Lactylated Proteomic Analysis Reveals Functional Implications of Lysine Lactylation In Asthenozoospermia.. Mol Cell Proteomics 24(12):101439. 2025 Dec. PMID: 41192556.