title: KLHL1/MRP2 mediates neurite outgrowth in a glycogen synthase kinase 3beta-dependent manner.
abstract: The actin-based cytoskeleton is essential for the generation and maintenance of cell polarity, cellular motility, and the formation of neural cell processes. MRP2 is an actin-binding protein of the kelch-related protein family. While MRP2 has been shown to be expressed specifically in brain, its function is still unknown. Here, we report that in neuronal growth factor (NGF)-induced PC12 cells, MRP2 was expressed along the neurite processes and colocalized with Talin at the growth cones. MRP2 mRNA and protein levels were up-regulated in PC12 cells following NGF stimulation. Moreover, treatment of PC12 cells with interfering RNAs for MRP2 and glycogen synthase kinase 3beta (GSK3beta) resulted in the inhibition of neurite outgrowth. A significant decrease in MRP2 expression levels was observed following GSK3beta inhibition, which was correlated with the inhibited neurite outgrowth, while GSK3beta overexpression was found to increase MRP2 expression levels. MRP2 interacted with GSK3beta through its NH2 terminus containing the BTB domain, and these molecules colocalized along neurite processes and growth cones in differentiated PC12 cells and rat primary hippocampal neurons. Additionally, increased associations of MRP2 with GSK3beta and MRP2 with actin were observed in the NGF-treated PC12 cells. Thus, this study provides, for the first time, insights into the involvement of MRP2 in neurite outgrowth, which occurs in a GSK3beta-dependent manner.
authors.affiliation: Division of Experimental Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Seyha
authors.initials: S
authors.lastname: Seng
authors.forename: Hava Karsenty
authors.initials: HK
authors.lastname: Avraham
authors.forename: Shuxian
authors.initials: S
authors.lastname: Jiang
authors.forename: Saritha
authors.initials: S
authors.lastname: Venkatesh
authors.forename: Shalom
authors.initials: S
authors.lastname: Avraham
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D002478:Cells, Cultured; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000502:physiology*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016501:Neurites / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D009474:Neurons / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D016716:PC12 Cells; D034741:RNA, Small Interfering / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D020917:Receptor, trkA / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D000199:Actins; C412617:KLHL1 protein, human; D008840:Microfilament Proteins; D034741:RNA, Small Interfering; D020932:Nerve Growth Factor; D020917:Receptor, trkA; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3