Emerin expression in early development of Xenopus laevis.
Emerin is an integral protein of the inner nuclear membrane in the majority of differentiated vertebrate cells. In humans, deficiency of emerin causes a progressive muscular dystrophy of the Emery-Dreifuss type. The physiological role of emerin is poorly understood. By screening and sequencing of EST clones we have identified two emerin homologues in Xenopus laevis, Xemerin1 and Xemerin2. Xemerins share with mammalian emerins the N-terminal LEM domain and a single transmembrane domain at the C-terminus. As shown by immunoblot analysis with Xemerin-specific antibodies, both proteins have an apparent molecular mass of 24 kDa but differ in their isoelectric points. Xemerin1 and Xemerin2 proteins are not detectable in oocytes nor during early embryogenesis. Protein expression is first found at stage 43 and persists in somatic cells. However, RT-PCR and Northern blot analysis show Xemerin mRNAs of approximately 4.0 kb to be present in oocytes and throughout embryogenesis. During embryogenesis the level of Xemerin mRNAs increases at stage 22 and is particularly abundant in mesodermal and neuro-ectodermal regions of the embryo. These data provide the necessary background to further investigate the role of emerin in nuclear envelope assembly, gene expression and organ development of X. laevis as a model organism.
Gareiss
Martin
M
Department of Cell and Developmental Biology, University of Würzburg, Biozentrum, Am Hubland, D-97074 Würzburg, Germany.
Eberhardt
Kathrin
K
Krüger
Eleonora
E
Kandert
Sebastian
S
Böhm
Carolin
C
Zentgraf
Hanswalter
H
Müller
Clemens R
CR
Dabauvalle
Marie-Christine
MC
D000595:Amino Acid Sequence; D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D009928:Organ Specificity / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013946:Thymopoietins / Q000235:genetics* / Q000378:metabolism; D014982:Xenopus laevis
D008565:Membrane Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D013946:Thymopoietins; C092710:emerin