title: Identification of nuclear/nucleolar localization signal in Aplysia learning associated protein of slug with a molecular mass of 18 kDa homologous protein.
abstract: We isolated a learning associated protein of slug with a molecular mass of 18 kDa (LAPS18) homologue from the expressed sequence tag database of Aplysia kurodai and named it Aplysia LAPS18-like protein (ApLLP). ApLLP encodes 120 amino acids and has 57% identity with LAPS18. To examine the subcellular expression pattern of ApLLP we constructed an EGFP-tagged ApLLP fusion protein and overexpressed it in both Aplysia neurons and COS-7 cells. In contrast to the previous findings, which showed that LAPS18 is secreted by COS-7 cells, ApLLP-EGFP was localized to the nucleus, and most of it to nucleoli. Analysis of deletion mutants of ApLLP-EGFP showed that the N-terminal and the C-terminal nucleolar and nucleus localization signal sequences are important for localization to the nucleus and the nucleoli.
authors.affiliation: National Research Laboratory, Institute of Molecular Biology and Genetics, School of Biological Sciences, College of Natural Sciences, Seoul National University, San 56-1 Silim-dong Kwanak-gu, Seoul 151-742, South Korea.
authors.forename: Hyoung
authors.initials: H
authors.lastname: Kim
authors.forename: Deok-Jin
authors.initials: DJ
authors.lastname: Chang
authors.forename: Jin-A
authors.initials: JA
authors.lastname: Lee
authors.forename: Yong-Seok
authors.initials: YS
authors.lastname: Lee
authors.forename: Bong-Kiun
authors.initials: BK
authors.lastname: Kaang
mesh_terms: D000818:Animals; D001048:Aplysia / Q000235:genetics*; D001483:Base Sequence; D001522:Behavior, Animal; D019556:COS Cells; D018076:DNA, Complementary; D015870:Gene Expression; D049452:Green Fluorescent Proteins; D007858:Learning / Q000502:physiology*; D008164:Luminescent Proteins; D009474:Neurons / Q000378:metabolism; D019913:Nuclear Localization Signals / Q000737:chemistry / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D011506:Proteins / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012984:Software; D013347:Subcellular Fractions / Q000378:metabolism; D014162:Transfection; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics
chemical_list: D018076:DNA, Complementary; C427663:LAPS18 protein, Limax marginatus; D008164:Luminescent Proteins; D019913:Nuclear Localization Signals; D011506:Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D049452:Green Fluorescent Proteins