Midkine and Pleiotrophin: Two Related Proteins Involved in Development, Survival, Inflammation and Tumorigenesis

摘要: Midkine (MK) and pleiotrophin (PTN) are low molecular weight proteins with closely related structures. They mainly composed of two domains held by disulfide bridges, there three antiparallel beta-sheets in each domain. MK PTN promote the growth, survival, migration various cells, play roles neurogenesis epithelial mesenchymal interactions during organogenesis. A chondroitin sulfate proteoglycan, protein-tyrosine phosphatase zeta (PTPzeta), is a receptor for PTN. The downstream signaling system includes ERK PI3 kinase. binds to portion PTPzeta high affinity. Among structures, E unit, which has 4,6-disulfated N-acetylgalactosamine, provides strongest binding site. expression increased human tumors, making them promising as tumor markers targets therapy. also increases upon ischemic injury. enhances inflammatory involved neointima formation renal injury following ischemia. interesting from viewpoints treatment neurodegenerative diseases, increasing efficiency vitro development, prevention HIV infection.