title: Conservation of the gene structure and membrane-targeting signals of germ cell-specific lamin LIII in amphibians and fish.
abstract: Targeting of nuclear lamins to the inner nuclear membrane requires CaaX motif-dependent posttranslational isoprenylation and carboxyl methylation. We previously have shown that two variants of lamin LIII (i.e., LIII and LIIIb) in amphibian oocytes are generated by alternative splicing and differ greatly in their membrane association. An extra cysteine residue (as a potential palmitoylation site) and a basic cluster in conjunction with the CaaX motif function as secondary targeting signals responsible for stable membrane association of lamin LIIIb. cDNA sequencing and genomic analysis of the zebrafish Danio rerio lamin LIII uncovers a remarkable conservation of the genomic organization and of the two secondary membrane-targeting signals in amphibians and fish. The expression pattern of lamin LIII genes is also conserved between amphibians and fish. Danio lamin LIII is expressed in diplotene oocytes. It is absent from male germ cells but is expressed in Sertoli cells of the testis. In addition, we provide sequence information of the entire coding sequence of zebrafish lamin A, which allows comparison of all major lamins from representatives of the four classes of vertebrates.
authors.affiliation: Department of Cell Biology, University of Bremen, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Hofemeister
authors.forename: Cäcilia
authors.initials: C
authors.lastname: Kuhn
authors.forename: Werner W
authors.initials: WW
authors.lastname: Franke
authors.forename: Klaus
authors.initials: K
authors.lastname: Weber
authors.forename: Reimer
authors.initials: R
authors.lastname: Stick
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D002451:Cell Compartmentation / Q000235:genetics; D004247:DNA / Q000235:genetics*; D005786:Gene Expression Regulation / Q000502:physiology; D005796:Genes / Q000235:genetics; D016678:Genome; D015698:Genomic Library; D005854:Germ Cells / Q000378:metabolism* / Q000648:ultrastructure; D007381:Intermediate Filament Proteins / Q000235:genetics* / Q000378:metabolism*; D034904:Lamin Type A; D034921:Lamin Type B; D034882:Lamins; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism* / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction / Q000235:genetics; D014982:Xenopus laevis / Q000033:anatomy & histology / Q000378:metabolism*; D015027:Zebrafish / Q000033:anatomy & histology / Q000378:metabolism*
chemical_list: D007381:Intermediate Filament Proteins; D034904:Lamin Type A; D034921:Lamin Type B; D034882:Lamins; D009687:Nuclear Proteins; D004247:DNA