Pleiotrophin

Pleiotrophin
Identifiers
Symbols	PTN ; HARP; HBGF8; HBNF; NEGF1
External IDs	OMIM: 162095 MGI: 97804 HomoloGene: 2117 GeneCards: PTN Gene
Gene ontology Molecular function • protein phosphatase inhibitor activity • growth factor activity • heparin binding • chondroitin sulfate proteoglycan binding Cellular component • extracellular space • endoplasmic reticulum • membrane • perinuclear region of cytoplasm Biological process • liver development • transmembrane receptor protein tyrosine phosphatase signaling pathway • nervous system development • learning • positive regulation of cell proliferation • positive regulation of cell-substrate adhesion • positive regulation of neuron projection development • response to activity • spinal cord development • bone mineralization • lung development • hindbrain development • cellular response to platelet-derived growth factor stimulus • response to drug • negative regulation of catalytic activity • negative regulation of membrane potential • positive regulation of cell division • retinal rod cell differentiation • long-term synaptic potentiation • cellular response to vitamin D • skeletal muscle acetylcholine-gated channel clustering • cellular response to hypoxia • response to nerve growth factor • positive regulation of hepatocyte proliferation Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	5764	19242
Ensembl	ENSG00000105894	ENSMUSG00000029838
UniProt	P21246	P63089
RefSeq (mRNA)	NM_002825	NM_008973
RefSeq (protein)	NP_002816	NP_032999
Location (UCSC)	Chr 7: 137.23 – 137.34 Mb	Chr 6: 36.72 – 36.81 Mb
PubMed search	[1]	[2]

Pleiotrophin (PTN) also known as heparin-binding brain mitogen (HBBM) or heparin-binding growth factor 8 (HBGF-8) or neurite growth-promoting factor 1 (NEGF1) or heparin affinity regulatory peptide (HARP) or heparin binding growth associated molecule (HB-GAM) is a protein that in humans is encoded by the PTN gene. Pleiotrophin is an 18-kDa growth factor that has a high affinity for heparin. It is structurally related to midkine and retinoic acid induced heparin-binding protein.

Function

Pleiotrophin was initially recognized as a neurite outgrowth-promoting factor present in rat brain around birthand as a mitogen toward fibroblasts isolated from bovine uterus tissue. Together with midkine these growth-factors constitute a family of (developmentally regulated) secreted heparin-binding proteins now known as the neurite growth-promoting factor (NEGF) family. During embryonic and early postnatal development, pleiotrophin is expressed in the central and peripheral nervous system and also in several non-neural tissues, notably lung, kidney, gut and bone. Pleiotrophin is also expressed by several tumor cells and is thought to be involved in tumor angiogenesis. In the adult central nervous system, pleiotrophin is expressed in an activity-dependent manner in the hippocampus where it can suppress long term potentiation induction. Pleiotrophin expression is low in other areas of the adult brain, but it can be induced by ischemic insults. or targeted neuronal damaged in the entorhinal cortex or in the substantia nigra pars compacta.

Clinical significance

Pleiotrophin binds to cell-surface nucleolin as a low affinity receptor. This binding can inhibit HIV infection.