Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Analysis was made on the genomic structure, functions, and expression of the mouse ELP gene, which codes for the embryonal long terminal repeat binding protein. Extensive screening of the cDNA library of embryonal carcinoma cells (EC cells) identified four isoforms of ELP: ELP1 (the original ELP isolate), ELP2, ELP3, and Ad4BP/SF1. Analysis of the genomic sequences revealed that these ELP isoforms were generated by alternative promoter usage and differential splicing. The mRNAs of isoforms initiated at four transcription start sites distributed on three exons. Sequence analysis of the four isoforms identified three polypeptides. The N-terminal portion of ELP1 and ELP2 was longer than ELP3, and Ad4BP/SF1 by 77 aa. The DNA-binding domain and region II were shared by all four isoforms. The C-terminal portion shared by ELP2, ELP3, and Ad4BP/SF1 was 131 aa in length, and that specific to ELP1 was 57 aa in length. The ELP3 and Ad4BP/SF1 isoforms were identical for the coding sequence, but the two differed at the 5' noncoding region. Region II and III domains of nuclear receptors were thought to be involved in ligand-binding and transcriptional activation. ELP1, which lacked region III, functioned as a repressor. The isoforms carrying intact region II and region III functioned as transactivators. Expression of the four isoforms was studied in mouse tissues and in tissue culture cells by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Complex patterns of expression of these isoforms were observed in various tissues. All four ELP isoforms were expressed only in EC cells.
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PMID:Genomic organization and isoforms of the mouse ELP gene. 854 74

FTZ-F1 is a member of the orphan nuclear receptors, which belongs to the steroid hormone receptor superfamily, and plays a role in the blastoderm and nervous system development in Drosophila. Recently, several FTZ-F1 family genes have been cloned in several species. SF-1/Ad4BPs have been identified as master regulators controlling steroidogenic P-450 genes in mammals and are considered to be the mammalian homologues of FTZ-F1. Moreover, SF-1/Ad4BP plays a critical role in the sexual differentiation of gonads in mammals. In vertebrates, except for mammals, the functional homologue of SF-1/Ad4BP has not been identified before. Herein, we cloned two chicken cDNAs (OR2.0 and OR2.1), which encode putative FTZ-F1 family receptors, by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). OR2.1 consists of 3255 bp, is expressed in the adrenal glands and gonads, and is considered to be the chicken counterpart of mammalian SF-1/Ad4BP. However, OR2.0 consists of 2945 bp, is expressed in the livers and the adrenal glands, and is considered to be the chicken counterpart of mouse LRH-1, which is a member of the FTZ-F1 family in mammals.
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PMID:Molecular cloning of chicken FTZ-F1-related orphan receptors. 933 74

Two nuclear receptors, Ad4BP/SF-1 and Dax-1, are essential regulators for development and function of the mammalian reproductive system. Similarity in expression sites, such as adrenal glands, gonads, pituitary, and hypothalamus, suggests a functional interaction, and the phenotype similarities were manifested in Ad4BP/SF-1-deficient mice and in cases of natural human mutations of Dax-1. In this study, quantitative reverse transcriptase polymerase chain reaction analyses revealed that expression profiles of Dax-1 in embryonic gonads are different between the two sexes and also from those of Ad4BP/SF-1. Immunohistochemical analyses clarified the spatial and temporal expressions of the Dax-1 protein during development of tissues composing the hypothalamic-pituitary-gonadal axis. During gonadal development, Dax-1 occurred after Ad4BP/SF-1 exhibiting a sexually dimorphic expression pattern at indifferent stages, indicating a possibility of Dax-1 involvement in earliest sex differentiation. When cord formation begins in the testis at embryonic day 12.5 (E12.5), Dax-1 was expressed strongly in Sertoli cells, but its expression level markedly decreased in Sertoli cells and increased in interstitial cells between E13.5 and E17.5. In the female, Dax-1 was strongly expressed in the entire ovarian primordium from E12.5 until E14.5, and then its expression level was decreased and limited to cells near the surface epithelium between E17.5 and postnatal day 0 (P0). During postnatal development of the testis, the variable staining of Dax-1 in Sertoli cells was detected as early as P7 and Dax-1-expressing Leydig cells became rare. In the postnatal ovary, Dax-1 expression was detected in granulosa cells with variable staining intensity, and occasionally in interstitial cells. During pituitary organogenesis, Dax-1 but not Ad4BP/SF-1 was expressed in the dorsal part of Rathke's pouch from E9.5. Later in development after E14.5, the distribution of Dax-1 overlapped with that of Ad4BP/SF-1, being restricted to gonadotropic cells in the anterior pituitary. In the ventromedial hypothalamus (VMH), Dax-1 and Ad4BP/SF-1 were mostly colocalized throughout the embryonic and postnatal development. Thus, the coexpression of Dax-1 and Ad4BP/SF-1 indicates their closely related functions in the development of the reproductive system. Furthermore, we noticed the presence of cells that express Dax-1 but not Ad4BP/SF-1, further indicating additional functions of Dax-1 in an Ad4BP/SF-1-independent molecular mechanism.
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PMID:Comparative localization of Dax-1 and Ad4BP/SF-1 during development of the hypothalamic-pituitary-gonadal axis suggests their closely related and distinct functions. 1130 69

Mice with disrupted mammalian PcG (Polycomb group) genes commonly show skeletal transformation of anterior-posterior identities. Disruption of the murine M33 gene, a PcG member, displayed posterior transformation of the vertebral columns and sternal ribs. In addition, failure of T-cell expansion and hypoplasia and sex-reversal of the gonads, have been observed. In the present study, we identified defects in the splenic and adrenal formation of M33-knock-out (KO) mice on a C57BL/6 genetic background. The spleen in these animals was smaller than in the wild-type mice and was spotted red because of nonuniform distribution of blood cells. Histologic examination revealed disorganization of the vascular endothelium and its surrounding structures, and immunohistochemistry demonstrated disturbances in vascular formation and colonization of immature hematopoietic cells. These splenic phenotypes observed in the M33-KO mice were quite similar to those seen in Ad4BP/SF1 (Nr5a1) knock-outs. Moreover, the adrenal glands of M33-KO and Ad4BP/SF1 heterozygous KO mice were smaller than those of the wild-type mice. Western blot, immunohistochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses of the M33 knock-outs all indicated significantly low expression of adrenal 4 binding protein/steroidogenic factor-1 (Ad4BP/SF-1), indicating that M33 is an essential upstream regulator of Ad4BP/SF1. In agreement with these observations, chromatin immunoprecipitation assays with adrenocortical Y-1 cells revealed direct binding of the M33-containing PcG to the Ad4BP/SF1 gene locus.
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PMID:Mouse Polycomb M33 is required for splenic vascular and adrenal gland formation through regulating Ad4BP/SF1 expression. 1589 14

Using semi-quantitative reverse transcriptase polymerase chain reaction we analyzed the ontogenic expression patterns of several nuclear receptors (estrogen receptors [ERalpha and beta], androgen receptors [ARalpha and beta], Ad4BP/SF-1 and Dax-1) and cytochrome P450 aromatases (brain and ovarian types) in whole brain and gonads of the Nile tilapia. ERalpha and beta transcripts were evident in both sexes with a high expression of ERalpha in females at 0 day after hatching (0 dah). ARalpha appeared early (0 dah) in males and while in females at 25 dah. Among the two types of cytochrome P450 aromatases, the expression of the brain type (bP450arom) but not the ovarian type (oP450arom) was evident from 0 to 90 dah in the whole brain of both males and females. Expression of Ad4BP/SF-1 in female brain began from 0 dah but in male brain at 5 dah. Expression of Dax-1 began at 0 dah and it was higher throughout in male brain than that of the female brain. In gonads, ERalpha and beta transcripts were evident in both sexes with slight variation. In females, both oP450arom and Ad4BP/SF-1 amplicons were evident at 15 dah. In males, although faint expressions of Ad4BP/SF-1 amplicons were evident at early duration of development, oP450arom did not appear until 90 dah. Conversely, expression of bP450arom was observed throughout in the developing testis with varied pattern while in developing ovary it was evident till 15 dah and reappeared only after 90 dah. Taken together, present results suggest that brain acts merely as a synchronizer in the sex differentiation process initiated by gonadal cues/factors in the Nile tilapia.
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PMID:Ontogenic expression patterns of several nuclear receptors and cytochrome P450 aromatases in brain and gonads of the Nile tilapia Oreochromis niloticus suggests their involvement in sex differentiation. 2003 46