title: Regulation of neuritogenesis and synaptic transmission by msec7-1, a guanine nucleotide exchange factor, in cultured Aplysia neurons.
abstract: msec7-1, a mammalian homologue of yeast sec7p, is known as a GDP/GTP exchange factor (GEF) for the ADP ribosylation factor (ARF) family of small GTPases. Here, we report that msec7-1 overexpression in cultured Aplysia neurons leads to an extensive neuritogenesis in a GEF activity-dependent manner through the modulation of the actin cytoskeleton. Similarly, the overexpression of ARNO, another mammalin GEF, produces extensive neuritogenesis in Aplysia neurons. In addition, msec7-1 overexpression increases the number of varicosities with an altered size and shape in a GEF activity-dependent manner. The overexpression of msec7-1 in pre-synaptic sensory neurons co-cultured with post-synaptic target motor neurons leads to an increase in the amplitude of the excitatory post-synaptic potential through its GEF activity. Our results demonstrate that msec7-1 regulates neuritogenesis and synaptic transmission.
authors.affiliation: National Research Laboratory of Neurobiology, Institute of Molecular Biology and Genetics, School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul, Korea.
authors.forename: Minjung
authors.initials: M
authors.lastname: Huh
authors.forename: Jin-Hee
authors.initials: JH
authors.lastname: Han
authors.forename: Chae-Seok
authors.initials: CS
authors.lastname: Lim
authors.forename: Seung-Hee
authors.initials: SH
authors.lastname: Lee
authors.forename: Seho
authors.initials: S
authors.lastname: Kim
authors.forename: Eunjoon
authors.initials: E
authors.lastname: Kim
authors.forename: Bong-Kiun
authors.initials: BK
authors.lastname: Kaang
mesh_terms: D000818:Animals; D001048:Aplysia; D002478:Cells, Cultured; D020690:GTPase-Activating Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*
chemical_list: C491661:Cyth 1 protein, rat; D020690:GTPase-Activating Proteins; D020662:Guanine Nucleotide Exchange Factors; C066755:Sec7 guanine nucleotide exchange factors; C102474:cytohesin-2