title: MPL1, a novel phosphatase with leucine-rich repeats, is essential for proper ERK2 phosphorylation and cell motility.
abstract: The novel Dictyostelium phosphatase MPL1 contains six leucine-rich repeats at the amino-terminal end and a phosphatase domain at the carboxyl end. Similarly architectured phosphatases exist among other protozoa, such as Entamoeba histolytica, Leishmania major, and Trypanosoma cruzi. MPL1 was strongly induced after 5 h of development; ablation by homologous recombination led to defective streaming and aggregation during development. In addition, cyclic AMP (cAMP)-pulsed mpl1(-) cells showed reduced random and directional motility. At the molecular level, mpl1(-) cells displayed higher prestimulus and persistent poststimulus ERK2 phosphorylation in response to cAMP stimulation. Consistent with their phenotype of persistent ERK2 phosphorylation, mpl1(-) cells also displayed an aberrant pattern of cAMP production, resembling that of the regA(-) cells. Reintroduction of a full-length MPL1 into mpl1(-) cells restored aggregation, ERK2 regulation, random and directional motility, and cAMP production similar to wild-type cells. We propose that MPL1 is a novel phosphatase essential for proper regulation of ERK2 phosphorylation and optimal motility during development.
authors.affiliation: Department of Biological Sciences, Florida International University, Miami, FL 33199, USA.
authors.forename: Marbelys
authors.initials: M
authors.lastname: Rodriguez
authors.forename: Bohye
authors.initials: B
authors.lastname: Kim
authors.forename: Nam-Sihk
authors.initials: NS
authors.lastname: Lee
authors.forename: Sudhakar
authors.initials: S
authors.lastname: Veeranki
authors.forename: Leung
authors.initials: L
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004023:Dictyostelium / Q000166:cytology / Q000201:enzymology* / Q000502:physiology; D056890:Eukaryota / Q000201:enzymology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D008969:Molecular Sequence Data; D009068:Movement; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000378:metabolism
chemical_list: D015800:Protozoan Proteins; D019950:Mitogen-Activated Protein Kinase 1; D010744:Phosphoric Monoester Hydrolases