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Identification of a cytokine-induced antiapoptotic molecule anamorsin essential for definitive hematopoiesis.

Shibayama H, Takai E, Matsumura I, Kouno M, Morii E, Kitamura Y, Takeda J, Kanakura Y - J. Exp. Med. (2004)

Bottom Line: Using an expression cloning method, we identified a novel antiapoptotic molecule named Anamorsin, which does not show any homology to known apoptosis regulatory molecules such as Bcl-2 family, caspase family, or signal transduction molecules.Also, Anamorsin-/- erythroid cells initiated apoptosis during terminal maturation.Thus, Anamorsin is considered to be a necessary molecule for hematopoiesis that mediates antiapoptotic effects of various cytokines.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology and Oncology, Osaka University Graduate School of Medicine, Yamada-oka, Suita, 565-0871, Japan.

ABSTRACT
Many growth factors and cytokines prevent apoptosis. Using an expression cloning method, we identified a novel antiapoptotic molecule named Anamorsin, which does not show any homology to known apoptosis regulatory molecules such as Bcl-2 family, caspase family, or signal transduction molecules. The expression of Anamorsin was completely dependent on stimulation with growth factors such as interleukin 3, stem cell factor, and thrombopoietin in factor-dependent hematopoietic cell lines, and forced expression of Anamorsin conferred resistance to apoptosis caused by growth factor deprivation in vitro. Furthermore, Anamorsin was found to act as an antiapoptotic molecule in vivo because Anamorsin-/- mice die in late gestation due to defective definitive hematopoiesis in the fetal liver (FL). Although the number of hematopoietic stem/progenitor cells in the FL did not decrease in these mice, myeloid, and particularly erythroid colony formation in response to cytokines, was severely disrupted. Also, Anamorsin-/- erythroid cells initiated apoptosis during terminal maturation. As for the mechanism of Anamorsin-mediated cell survival, a microarray analysis revealed that the expression of Bcl-xL and Jak2 was severely impaired in the FL of Anamorsin-/- mice. Thus, Anamorsin is considered to be a necessary molecule for hematopoiesis that mediates antiapoptotic effects of various cytokines.

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Anamorsin confers resistance to apoptosis caused by IL-3 depletion in Ba/F3 cells. (a) Anamorsin cDNA sequence and corresponding amino acid sequence. The underlined amino acid sequence shows generic methyltransferase motif. (b and c) Ba/F3 cells transfected with an empty vector or Anamorsin (AM) cDNA were deprived of IL-3 for the time indicated and the apoptotic cells were subjected to DNA content analysis (b) and caspase-3 assays (c).
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fig1: Anamorsin confers resistance to apoptosis caused by IL-3 depletion in Ba/F3 cells. (a) Anamorsin cDNA sequence and corresponding amino acid sequence. The underlined amino acid sequence shows generic methyltransferase motif. (b and c) Ba/F3 cells transfected with an empty vector or Anamorsin (AM) cDNA were deprived of IL-3 for the time indicated and the apoptotic cells were subjected to DNA content analysis (b) and caspase-3 assays (c).

Mentions: By sequencing the integrated cDNA, we found that the coding region of a murine protein, Anamorsin, cDNA consisted of 930 bp (Fig. 1 a). Comparison with a DNA database search revealed that the sequence of Anamorsin does not exhibit homology with any known antiapoptotic molecules, including Bcl-2 family proteins, caspase inhibitors, or signal transduction molecules. Also, we found a human homologue of Anamorsin in GenBank data libraries, which revealed 82.6% similarity to murine Anamorsin at the DNA level and 81.9% similarity at the amino acid level. The human homologue of Anamorsin was originally found by Loftus et al. (27) as a molecule with unknown function on chromosome 16 (sequence data are available from GenBank/EMBL/DDBJ under accession no. AC004382). Anamorsin encodes a protein with a molecular weight of ∼37 kD and the protein sequence database indicates that Anamorsin has a generic methyltransferase motif around amino acids 60–99 (Fig. 1 a).


Identification of a cytokine-induced antiapoptotic molecule anamorsin essential for definitive hematopoiesis.

Shibayama H, Takai E, Matsumura I, Kouno M, Morii E, Kitamura Y, Takeda J, Kanakura Y - J. Exp. Med. (2004)

Anamorsin confers resistance to apoptosis caused by IL-3 depletion in Ba/F3 cells. (a) Anamorsin cDNA sequence and corresponding amino acid sequence. The underlined amino acid sequence shows generic methyltransferase motif. (b and c) Ba/F3 cells transfected with an empty vector or Anamorsin (AM) cDNA were deprived of IL-3 for the time indicated and the apoptotic cells were subjected to DNA content analysis (b) and caspase-3 assays (c).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211823&req=5

fig1: Anamorsin confers resistance to apoptosis caused by IL-3 depletion in Ba/F3 cells. (a) Anamorsin cDNA sequence and corresponding amino acid sequence. The underlined amino acid sequence shows generic methyltransferase motif. (b and c) Ba/F3 cells transfected with an empty vector or Anamorsin (AM) cDNA were deprived of IL-3 for the time indicated and the apoptotic cells were subjected to DNA content analysis (b) and caspase-3 assays (c).
Mentions: By sequencing the integrated cDNA, we found that the coding region of a murine protein, Anamorsin, cDNA consisted of 930 bp (Fig. 1 a). Comparison with a DNA database search revealed that the sequence of Anamorsin does not exhibit homology with any known antiapoptotic molecules, including Bcl-2 family proteins, caspase inhibitors, or signal transduction molecules. Also, we found a human homologue of Anamorsin in GenBank data libraries, which revealed 82.6% similarity to murine Anamorsin at the DNA level and 81.9% similarity at the amino acid level. The human homologue of Anamorsin was originally found by Loftus et al. (27) as a molecule with unknown function on chromosome 16 (sequence data are available from GenBank/EMBL/DDBJ under accession no. AC004382). Anamorsin encodes a protein with a molecular weight of ∼37 kD and the protein sequence database indicates that Anamorsin has a generic methyltransferase motif around amino acids 60–99 (Fig. 1 a).

Bottom Line: Using an expression cloning method, we identified a novel antiapoptotic molecule named Anamorsin, which does not show any homology to known apoptosis regulatory molecules such as Bcl-2 family, caspase family, or signal transduction molecules.Also, Anamorsin-/- erythroid cells initiated apoptosis during terminal maturation.Thus, Anamorsin is considered to be a necessary molecule for hematopoiesis that mediates antiapoptotic effects of various cytokines.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology and Oncology, Osaka University Graduate School of Medicine, Yamada-oka, Suita, 565-0871, Japan.

ABSTRACT
Many growth factors and cytokines prevent apoptosis. Using an expression cloning method, we identified a novel antiapoptotic molecule named Anamorsin, which does not show any homology to known apoptosis regulatory molecules such as Bcl-2 family, caspase family, or signal transduction molecules. The expression of Anamorsin was completely dependent on stimulation with growth factors such as interleukin 3, stem cell factor, and thrombopoietin in factor-dependent hematopoietic cell lines, and forced expression of Anamorsin conferred resistance to apoptosis caused by growth factor deprivation in vitro. Furthermore, Anamorsin was found to act as an antiapoptotic molecule in vivo because Anamorsin-/- mice die in late gestation due to defective definitive hematopoiesis in the fetal liver (FL). Although the number of hematopoietic stem/progenitor cells in the FL did not decrease in these mice, myeloid, and particularly erythroid colony formation in response to cytokines, was severely disrupted. Also, Anamorsin-/- erythroid cells initiated apoptosis during terminal maturation. As for the mechanism of Anamorsin-mediated cell survival, a microarray analysis revealed that the expression of Bcl-xL and Jak2 was severely impaired in the FL of Anamorsin-/- mice. Thus, Anamorsin is considered to be a necessary molecule for hematopoiesis that mediates antiapoptotic effects of various cytokines.

Show MeSH