title: The role of Munc18-1 and its orthologs in modulation of cortical F-actin in chromaffin cells.
abstract: Munc18-1 was originally described as an essential docking factor in chromaffin cells. Recent findings showed that Munc18-1 has an additional role in the regulation of the cortical F-actin network, which is thought to function as a physical barrier preventing secretory vesicles from access to their release sites under resting conditions. In our review, we discuss whether this function is evolutionarily conserved in all Sec1/Munc18-like (SM) proteins. In addition, we introduce a new quantification method that improves the analysis of cortical filamentous actin (F-actin) in comparison with existing methods. Since the docking process is highly evolutionarily conserved in the SM protein superfamily, we use our novel quantification method to investigate whether the F-actin-regulating function is similarly conserved among SM proteins. Our preliminary data suggest that the regulation of cortical F-actin is a shared function of SM proteins, and we propose a way to gain more insight in the molecular mechanism underlying the Munc18-1-mediated cortical F-actin regulation.
authors.affiliation: Department of Functional Genomics and Clinical Genetics, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam and VU University Medical Center, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
authors.forename: Julia
authors.initials: J
authors.lastname: Kurps
authors.forename: Heidi
authors.initials: H
authors.lastname: de Wit
mesh_terms: D000199:Actins / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D019439:Chromaffin Cells / Q000166:cytology / Q000502:physiology*; D003584:Cytological Techniques / Q000379:methods; D051379:Mice; D018345:Mice, Knockout; D051938:Munc18 Proteins / Q000235:genetics / Q000502:physiology*; D022142:Secretory Vesicles / Q000235:genetics / Q000502:physiology*
chemical_list: D000199:Actins; D051938:Munc18 Proteins; C497938:Stxbp1 protein, mouse; C497941:Stxbp2 protein, mouse