Midkine (MDK) Human Active Protein

This gene encodes a member of a small family of secreted growth factors that binds heparin and responds to retinoic acid. The encoded protein promotes cell growth, migration, and angiogenesis, in particular during tumorigenesis. This gene has been targeted as a therapeutic for a variety of different disorders. Alternatively spliced transcript variants encoding multiple isoforms have been observed. [provided by RefSeq, Jul 2012]

MDK: Developmentally regulated, secreted growth factor homologous to pleiotrophin (PTN), which has heparin binding activity. 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. Involved in neointima formation after arterial injury, possibly by mediating leukocyte recruitment. Also involved in early fetal adrenal gland development. Belongs to the pleiotrophin family.

Protein type: Secreted, signal peptide; Secreted

Chromosomal Location of Human Ortholog: 11p11.2

Cellular Component: cell projection; cytoplasm; extracellular region

Molecular Function: heparin binding; growth factor activity

Biological Process: response to drug; nervous system development; cell migration; Notch signaling pathway; dentate gyrus development; behavioral fear response; short-term memory; adrenal gland development; cerebellar granular layer development; positive regulation of transcription, DNA-dependent; response to glucocorticoid stimulus; signal transduction; positive regulation of cell division; response to wounding; negative regulation of neuron apoptosis; cerebral cortex development; cell differentiation; defecation; regulation of behavior