Structure, sequence and function of a marsupial LIF gene: conservation of IL-6 family cytokines.
Leukaemia Inhibitory Factor (LIF) is a multifunctional cytokine with an obligate role in the mouse in embryonic implantation. In this paper we demonstrate the existence of a functional LIF gene in the marsupial Sminthopsis crassicaudata, and the presence of LIF-related sequences in the monotreme Tachyglossus aculeatus (Australian echidna). Isolation of genomic and cDNA clones from S. crassicaudata, indicated that the LIF gene is highly conserved between marsupials and monotremes in terms of sequence and genomic organisation. Critical functional residues within the LIF sequence were also conserved including residues implicated in intracellular LIF activity, and in interaction with the receptor subunits LIFR and gp130. These findings suggest that the structure and biochemical function of the protein is likely to be conserved. Consistent with this, purified recombinant S. crassicaudata LIF interacted functionally with mouse receptor components and was sufficient for maintenance of mouse embryonic stem (ES) cells in the undifferentiated state. Conservation of LIF outside eutherians is intriguing given the markedly divergent reproductive strategies which include, for some marsupial species, embryonic diapause, and in monotremes, the absence of implantation. The availability of marsupial LIF probes provides an opportunity to investigate conservation of expression and function in these mammals.
Cui
S
S
Department of Molecular Biosciences, University of Adelaide, Adelaide, Australia.
Hope
R M
RM
Rathjen
J
J
Voyle
R B
RB
Rathjen
P D
PD
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D015139:Blotting, Southern; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D017124:Conserved Sequence / Q000235:genetics*; D050822:Cytokine Receptor gp130; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D006131:Growth Inhibitors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D015850:Interleukin-6 / Q000737:chemistry* / Q000235:genetics; D007438:Introns / Q000235:genetics; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D008394:Marsupialia / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D009007:Monotremata / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics*; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology; D016415:Sequence Alignment; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects
D015703:Antigens, CD; D006131:Growth Inhibitors; C494200:Il6st protein, mouse; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D008222:Lymphokines; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D050822:Cytokine Receptor gp130