Cloning, sequencing and expression of stem cell factor (c-kit ligand) cDNA of brushtail possum (Trichosurus vulpecula)

1996 ◽  
Vol 8 (4) ◽  
pp. 789 ◽  
Author(s):  
PJ Greenwood ◽  
C Seamer ◽  
DJ Tisdall

By means of reverse transcription polymerase chain reaction (RT-PCR), three stem cell factor (SCF) cDNAs (822-738 bp in size) were amplified from brushtail possum ovarian poly (A)+ RNA. The largest and smallest of these cDNAs were cloned and sequenced. Characterization of these cDNAs has revealed that possum SCF has approximately 75% and 66% homology to SCF of eutherian mammals at the nucleotide level and the predicted amino acid level respectively. Nucleotide sequencing shows that the 738-bp cDNA represents an mRNA splice variant, equivalent to that found in eutherian mammals, in which an exon (84 bp) encoding a potential proteolytic cleavage site is removed. Comparison of the predicted possum SCF amino acid sequence with the predicted SCF amino acid sequences from eutherian mammals reveals conservation of all cysteine residues and 3 of 4 potential N-linked glycosylation sites. In addition, the hydropathicity profile of the possum SCF protein is similar to that of eutherian SCF suggesting that protein conformation is conserved. Northern analysis was used to characterize possum SCF gene expression in adult ovary and testis. A major transcript of 9 kb was observed in both ovarian and testicular tissue. The conservation of the SCF gene and its predicted protein, suggests that SCF in the possum has similar biological activities to SCF in eutherian mammals.

1997 ◽  
Vol 18 (2) ◽  
pp. 127-135 ◽  
Author(s):  
D J Tisdall ◽  
L D Quirke ◽  
P Smith ◽  
K P McNatty

ABSTRACT Two ovine stem cell factor (oSCF) cDNAs (822 bp and 738 bp) were generated from ovarian follicle mRNA by RT-PCR. Nucleotide sequencing revealed that the oSCF 822 bp cDNA encodes a precursor protein of 274 amino acids. An amino acid change 109E to 109Q was the only sequence difference from that previously described for this species. The smaller (738 bp) oSCF cDNA was shown by nucleotide sequencing to be an mRNA splice variant, equivalent to that found in other mammals, in which an exon (84 bp) encoding a potential proteolytic cleavage site is removed. Northern analysis revealed a single transcript of approximately 6·5 kb in follicles, corpora lutea and stroma of mid-luteal sheep ovaries. In situ hybridization was used to detect oSCF mRNA within ovaries of fetal sheep on days 90, 100, 120 and 135 of gestation (term=147) and of adult sheep within the breeding season. In fetal and adult ovaries, oSCF mRNA was detected in the granulosa cells of follicles at all stages of follicle growth (primordial through to antral). The SCF gene was also expressed in granulosa cells of atretic follicles but appeared to be down-regulated in the cumulus cells surrounding the oocyte at more advanced stages of atresia. In fetal ovaries at day 90 of gestation (90DG), oSCF was expressed in the subepithelial mesenchymal cells of the ovarian cortex. By 100DG the gene expression in the subepithelial cells became restricted to a narrow region below the epithelium, and areas of expression were observed in groups of cells around isolated oocytes, primordial and primary follicles. oSCF gene expression also occurred in the surface epithelial cells of 90DG ovaries, the expression was absent from these cells by 135DG and in adult ovaries. Localization of oSCF mRNA was observed in the ovarian rete and endothelial cells of blood vessels of fetal ovaries. These results suggest that oSCF may have an important and continuous role in the development and/or maintenance of germ cells during follicle growth and atresia in sheep.


1994 ◽  
Vol 14 (2) ◽  
pp. 1431-1437 ◽  
Author(s):  
B Samal ◽  
Y Sun ◽  
G Stearns ◽  
C Xie ◽  
S Suggs ◽  
...  

A novel gene coding for the pre-B-cell colony-enhancing factor (PBEF) has been isolated from a human peripheral blood lymphocyte cDNA library. The expression of this gene is induced by pokeweed mitogen and superinduced by cycloheximide. It is also induced in the T-lymphoblastoid cell line HUT 78 after phorbol ester (phorbol myristate acetate) treatment. The predominant mRNA for PBEF is approximately 2.4 kb long and codes for a 52-kDa secreted protein. The 3' untranslated region of the mRNA has multiple TATT motifs, usually found in cytokine and oncogene messages. The PBEF gene is mainly transcribed in human bone marrow, liver tissue, and muscle. We have expressed PBEF in COS 7 and PA317 cells and have tested the biological activities of the conditioned medium as well as the antibody-purified protein in different in vitro assays. PBEF itself had no activity but synergized the pre-B-cell colony formation activity of stem cell factor and interleukin 7. In the presence of PBEF, the number of pre-B-cell colonies was increased by at least 70% above the amount stimulated by stem cell factor plus interleukin 7. No effect of PBEF was found with cells of myeloid or erythroid lineages. These data define PBEF as a novel cytokine which acts on early B-lineage precursor cells.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


2004 ◽  
Vol 279 (45) ◽  
pp. 46706-46714 ◽  
Author(s):  
Alfonso Catalano ◽  
Sabrina Rodilossi ◽  
Maria Rita Rippo ◽  
Paola Caprari ◽  
Antonio Procopio

2018 ◽  
Vol 36 ◽  
pp. e294-e295
Author(s):  
Muhammad Nabeel Dookhun ◽  
Hai-Lan Zhong ◽  
Ya-Li Sun ◽  
Xiao-Qian Cao ◽  
Hua-Yi Yang Zou ◽  
...  

Endocrinology ◽  
1997 ◽  
Vol 138 (6) ◽  
pp. 2347-2353 ◽  
Author(s):  
Yan Chun Li ◽  
Clemens Bergwitz ◽  
Harald Jüppner ◽  
Marie B. Demay

Abstract The Vitamin D receptor (VDR), a member of the nuclear receptor superfamily, mediates the effects of 1,25-dihydroxyvitamin D3 on mineral ion homeostasis. Although the mammalian and avian VDRs have been extensively studied, little is known about the VDR in lower vertebrate species. To address this, we have isolated the Xenopus laevis VDR (xVDR) complementary DNA. Overall, the xVDR shares 79%, 73%, 73%, and 75% identity at the amino acid level with the chicken, mouse, rat, and human VDRs, respectively. The amino acid residues and subdomains important for DNA binding, hormone binding, dimerization, and transactivation are mostly conserved among all VDR species. The xVDR polypeptide can heterodimerize with the mouse retinoid X receptor α, bind to the rat osteocalcin vitamin D response element (VDRE), and induce vitamin D-dependent transactivation in transfected mammalian cells. Northern analysis reveals two xVDR messenger RNA species of 2.2 kb and 1.8 kb in stage 60 Xenopus tissues. In the adult, xVDR expression is detected in many tissues including kidney, intestine, skin, and bone. During Xenopus development, xVDR messenger RNA first appears at developmental stage 13 (preneurulation), increasing to maximum at stages 57–61 (metamorphosis). Our data demonstrate that, in Xenopus, VDR expression is developmentally regulated and that the vitamin D endocrine system is highly conserved during evolution.


Blood ◽  
2002 ◽  
Vol 100 (4) ◽  
pp. 1274-1286 ◽  
Author(s):  
Jesus Pérez-Losada ◽  
Manuel Sánchez-Martı́n ◽  
Arancha Rodrı́guez-Garcı́a ◽  
Maria Luz Sánchez ◽  
Alberto Orfao ◽  
...  

The stem cell factor c-kit signaling pathway (SCF/c-kit) has been previously implicated in normal hematopoiesis, melanogenesis, and gametogenesis through the formation and migration of c-kit+ cells. These biologic functions are also determinants in epithelial–mesenchymal transitions during embryonic development governed by the Snail family of transcription factors. Here we show that the activation of c-kit by SCF specifically induces the expression of Slug, a Snail family member. Slug mutant mice have a cell-intrinsic defect with pigment deficiency, gonadal defect, and impairment of hematopoiesis. Kit+ cells derived from Slug mutant mice exhibit migratory defects similar to those of c-kit+ cells derived from SCF and c-kit mutant mice. Endogenous Slug is expressed in migratory c-kit+ cells purified from control mice but is not present in c-kit+cells derived from SCF mutant mice or in bone marrow cells from W/Wv mice, though Slug is present in spleen c-kit+ cells of W/Wv (mutants expressing c-kit with reduced surface expression and activity). SCF-induced migration was affected in primary c-kit+ cells purified from Slug−/− mice, providing evidence for a role of Slug in the acquisition of c-kit+ cells with ability to migrate. Slug may thus be considered a molecular target that contributes to the biologic specificity to the SCF/c-kit signaling pathway, opening up new avenues for stem cell mobilization.


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