Albumin Phylogeny for Clawed Frogs (
            <i>Xenopus</i>
            )

Bisbee, C. A.; Baker, Margaret; Wilson, Allan C.; Haji-Azimi, Irandokht; Fischberg, M.

doi:10.1126/science.65013

Cited by 360 publications

(172 citation statements)

References 30 publications

Supporting

Mentioning

153

Contrasting

Order By: Relevance

“…These gene pairs are believed to represent duplicated genes resulting from a duplication of the entire genome in the genus Xenopus [23]. The two PC2 genes were found to be expressed to approximately the same level in the pituitary pars inter- media, similar to the expression of the two Xetmpus POMC genes [22].…”

Section: Discussionmentioning

confidence: 97%

Structure and expression of Xenopus prohormone convertase PC2

et al. 1992

View full text Add to dashboard Cite

The multifunctional prohormonc, proopiomclanocortin (POMC), is processsd in the melanotropc cells of the pituitary pars intprmedia at pairs of basic amino acid residues to give a number of pcptides, including a-melanophorc-stimulating hormone (o-MSH). This hormone causes skin darkening in amphibians during background adaptation. Here WC report the complete structure of XLWU~ILS IueGs prohonnonc convcrtasc PC?, the enzyme thought to be responsible for processing of POMC to a-MSH. A comparative structural analysis revealed an overall aminoacid sequence identity of85-87% between Xctt~pus PC2 and its mammalian counterparts, with the lowest degree ofidcntity in the signal peptidrsequcmx (28-368) and the region amino+zrmintil to the catalytic domain (59-608). The occurrence of a second, structurally different PC2 protein reflects the expression of two ,%'crro(l~rs PC2 penes. The expression pattern of PC2 in the XLWII~US pituitary gland of black-and white-adapted anhnals was found to be similar to that of POMC, namely high expression in active mclanotrope cells of black animals. This observation is in lint with a physiological role for PC2 in processing POMC to a-MSH.

show abstract

Section: Discussionmentioning

confidence: 97%

Structure and expression of Xenopus prohormone convertase PC2

et al. 1992

View full text Add to dashboard Cite

show abstract

“…The microheterogeneities observed probably arise from the quasi-tetrapolid genome of X. laevis [17] resulting from a duplication of the genome about 30 million years ago [ 181. This long time period could easily account for the evolutionary drift of these two sets of genes.…”

Section: Nucleic Acid Sequencementioning

confidence: 99%

Amino acid sequence microheterogeneities of a type I cytokeratin of M_r 51 000 from Xenopus laevis epidermis

Hoffmann¹,

Sterrer²,

Königstorfer³

1988

FEBS Letters

View full text Add to dashboard Cite

The complete cDNA-derived sequence of a type I cytokeratin (designated no. 3) from Xenopus laevis skin is described. The deduced protein has an M, of 51888 and consists of a glycine-rich head domain, a well-conserved a-helical region and a tail rich in hydroxyamino acid residues. Various cDNA clones encoding two different mRNAs were isolated that differed by short deletions/insertions and point mutations. These microheterogeneities are mainly located in a 'hypervariable region' at the C-terminal non-a-helical region.

show abstract

“…taevis gene pairs for globins A and B [22], albumins A and B [23], vitellogenins A and B [24], proenkephalins A and B [25], and proopiomelanocortins A and B [26]. The gene pairs are probably the result of a duplication of the entire genome in the genus Xenopus some 30-50 million years ago [27]. We therefore conclude that cDNA clones pHRlXD2 and pE4RIXD2 correspond to transcripts of two Xenopus D,-dopamine-receptor genes, gene A and gene B, respectively.…”

Section: Resultsmentioning

confidence: 99%

Expression of the Xenopus D₂ dopamine receptor

Martens

Groenen

Gröneveld

et al. 1993

European Journal of Biochemistry

View full text Add to dashboard Cite

In the amphibian Xenopus Zuevis the D, dopamine receptor is involved in the regulation of the melanotrope cells of the intermediate pituitary during background adaptation of the animal. The Xenopus D, receptor has been found to be pharmacologically different from the mammalian D, receptor. In a number of mammalian species alternative splicing generates two molecular forms of the D, receptor. These isoforms differ by the presence or absence of 29 amino acids in the third cytoplasmic loop which is thought to be involved in guanine-nucleotide-binding-regulatory-protein (G-protein) binding of the receptor. We previously described a cDNA encoding the large isoform of the Xenopus D, receptor. Here we report on the isolation of a brain cDNA encoding a second, structurally different Xenopus D, dopamine receptor. Both Xenopus receptors correspond to the large isoform of the D, receptor and they display a high degree of sequence identity with their mammalian counterparts. Their occurrence reflects the expression of two Xenopus D, receptor genes and they are expressed to approximately the same level. In contrast to mammals, PCR analysis gave no evidence for alternative splicing during D, receptor expression in Xenopus brain and pituitary. Tissue-specific expression of the Xenopus D, receptor was observed in the pituitary during background adaptation. The low level of receptor mRNA in melanotrope cells of white animals compared to that of black animals may be caused by chronic dopamine stimulation of melanotrope cells in white animals with consequent cellular desensitization and down regulation of the D, receptor gene.Recent cloning of cDNA and genomic DNA fragments has revealed the existence of a number of dopamine-receptor subtypes, namely the D1, D,, DS, D, and D, receptors [l-71. These receptors, which belong to the family of guaninenucleotide-binding-regulatory-protein(G-protein)-coupled receptors, are characterized by the presence of seven putative membrane-spanning domains within their structures [S]. The diversity of dopamine receptors is probably generated by gene duplication events. The D, and D, receptors are structurally and functionally related, and they are encoded by intronless genes. In contrast, the genes encoding the structurally and functionally related D,, D, and D, receptors all contain a number of introns. The structural and functional relationships between the dopamine-receptor subtypes D, and D, on the one hand, and DZ, D, and D4 on the other, may reflect their evolutionary history. In human, bovine, rat and Note. The novel nucleotide sequence data published here has beeen deposited with the EMBL sequence data banks and is available under accession number X72902. mouse the degree of diversity of dopamine-receptor subtypes is further increased by alternative splicing of D,-dopaminereceptor-gene transcripts which results in D, , and D,, receptor subtypes [9-131. The D, receptor isoforms differ from each other by the presence or absence of 29 amino-acid residues in the third cytoplasmic loop. Cells tran...

show abstract

Albumin Phylogeny for Clawed Frogs ( Xenopus )

Cited by 360 publications

References 30 publications

Structure and expression of Xenopus prohormone convertase PC2

Structure and expression of Xenopus prohormone convertase PC2

Amino acid sequence microheterogeneities of a type I cytokeratin of M_r 51 000 from Xenopus laevis epidermis

Expression of the Xenopus D₂ dopamine receptor

Contact Info

Product

Resources

About

Albumin Phylogeny for Clawed Frogs ( Xenopus )

Cited by 360 publications

References 30 publications

Structure and expression of Xenopus prohormone convertase PC2

Structure and expression of Xenopus prohormone convertase PC2

Amino acid sequence microheterogeneities of a type I cytokeratin of Mr 51 000 from Xenopus laevis epidermis

Expression of the Xenopus D2 dopamine receptor

Contact Info

Product

Resources

About

Amino acid sequence microheterogeneities of a type I cytokeratin of M_r 51 000 from Xenopus laevis epidermis

Expression of the Xenopus D₂ dopamine receptor