title: A function for the calponin family member NP25 in neurite outgrowth.
abstract: The neuronal protein 25 (NP25), a member of the calponin (CaP) protein family, has previously been identified as neuron-specific protein in the adult rat brain. Here, we show an early onset of NP25 expression in the chick embryo neural tube. NP25 represents, together with NeuroM, one of the earliest markers for postmitotic neurons. To elucidate its function in the developing nervous system, NP25 was overexpressed in E5 and E9 sensory neurons, E7 sympathetic neurons and PC12 cells that show different endogenous NP25 expression levels. Whereas E5 and E9 sensory neurons and PC12 cells, which express low endogenous levels of NP25, responded by enhanced neurite outgrowth, a reduction of neurite length was observed in sympathetic neurons, which already express high endogenous levels of NP25. Knockdown of NP25 in sensory neurons using NP25 siRNA resulted in shorter neurites, whereas reduction of NP25 expression in sympathetic neurons led to increased neurite length. These results suggest a dynamic function for NP25 in the regulation of neurite growth, with an optimal level of NP25 required for maximal growth.
authors.affiliation: Max-Planck-Institute for Brain Research, Deutschordenstr. 46, 60528 Frankfurt/M, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Pape
authors.forename: Epaminondas
authors.initials: E
authors.lastname: Doxakis
authors.forename: Tobias
authors.initials: T
authors.lastname: Reiff
authors.forename: Chi Vinh
authors.initials: CV
authors.lastname: Duong
authors.forename: Alun
authors.initials: A
authors.lastname: Davies
authors.forename: Markus
authors.initials: M
authors.lastname: Geissen
authors.forename: Hermann
authors.initials: H
authors.lastname: Rohrer
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D002642:Chick Embryo; D017403:In Situ Hybridization; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D054259:Neural Tube / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D034622:RNA Interference; D051381:Rats; D000096985:Calponins
chemical_list: D001973:Bromodeoxyuridine; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D000096985:Calponins