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M Ayane

Publications and source records attributed to M Ayane.

10 recordsLinked to original sources
PubMed1995

The ribose 5-phosphate isomerase-encoding gene is located immediately downstream from that encoding murine immunoglobulin kappa.

The immunoglobulin kappa locus (Ig kappa) is active only in the B-lymphocyte cell lineage. By exon-trapping we found a gene situated downstream from the murine Ig kappa locus. This gene encodes a protein with 53% sequence identity to the ribose 5-phosphate isomerase A (RPI-A) of Escherichia coli and is therefore likely to be the murine homologue (mRPI) of this enzyme. We confirmed this assumption by showing that a glutathione S-transferase (GST)::mRPI fusion protein has enzymatic activity and that an anti-mRPI antibody detects a protein of the predicted mass of RPI (33 kDa). Cloning and sequencing of the human counterpart show that the RPI gene is evolutionarily conserved. The expression of mRPI is not influenced by the rearrangement status of the Ig kappa locus in B cells and mRPI is expressed in all tissues. We thus show that two genes with very different expression patterns, a housekeeping gene and a gene expressed in a tissue-specific manner, can be located on a chromosome in close proximity to each other.

Aldose-Ketose Isomerases↗
PubMed1993

Cloning and sequencing of a cDNA fragment from Plasmodium chabaudi chabaudi that contains repetitive sequences coding for a potentially lysine-rich aspartic acid-rich protein.

Screening of a cDNA library (prepared in lambda gt11) of the blood stages of Plasmodium chabaudi chabaudi (AS) with immune serum has revealed an antigen the elicits a strong antibody response in infected mice. The clone (clone 6) expressing that antigen contains a 0.7 kb insert and produces a beta-galactosidase fusion protein of about 150 kDa. In Western blot analysis performed on parasite extracts, monoclonal antibodies and polyclonal sera prepared against the fusion protein revealed that the fusion protein contains part of a malarial protein of 93 kDa. Northern hybridization with clone 6 insert as probe detected a plasmodial RNA of about 3.2 kb, which could well code for a protein of this size. The insert hybridized to a single EcoRI fragment and a single HindIII fragment in genomic Southern blotting, suggesting that the gene is present in one copy in the P. chabaudi genome. The DNA sequence of clone 6 insert predicts a hydrophilic, acidic polypeptide consisting of seven repeats of 23-34 amino acids rich in lysine (24%) and aspartic acid (17.5%).

Amino Acid Sequence↗
PubMed1991

Screening cDNA expression libraries in lambda gt11 with a T cell hybridoma.

A T cell hybridoma specific for a protein of Plasmodium chabaudi chabaudi has been used to test a system for direct T cell screening of a cDNA library of P. chabaudi in the phage lambda gt11. The technique is based upon the rapid separation of the recombinant beta-galactosidase fusion protein from the bacterial mixtures using polystyrene beads coated with anti-beta-galactosidase antibodies. These coated beads are cultured with antigen-presenting cells and the T cell hybridoma. The technique is sufficiently sensitive to pick up the products of one recombinant phage in a pool of 1000-10,000 other phages. Individual plaques or clones of recombinant phage can be selected after testing of sequential dilutions of pools containing positive recombinant phages. This technique will be generally applicable and should be useful for the identification of important T cell peptides in infectious diseases.

Animals↗
PubMed1991

A differentially expressed murine RNA encoding a protein with similarities to two types of nucleic acid binding motifs.

Using differential screening, a murine cDNA, termed X16, was isolated corresponding to an mRNA which is more strongly expressed in pre-B cell lines relative to mature B-cell lines. The complete coding sequence of the mRNA predicts a 19kD protein with two domains connected by a proline-rich spacer. The N-terminal domain of about 90 amino acids encodes an RNA binding motif including the ribonucleoprotein consensus octapeptide found in one class of RNA-binding proteins and highly conserved from yeast to man. Within the very basic C-terminal domain of about 60 amino acids, several copies of two different peptides are found which are also present in several proteins which bind DNA or RNA. The expression of X16 is not limited to the lymphoid lineage. In adult mice, although the strongest expression was seen in thymus, mRNA was also found in testis, brain, spleen, and very low in heart. X16 mRNA was not detected in liver and kidney. In tissue culture, the expression of X16 mRNA can be induced by serum. The conserved protein motifs and expression pattern suggest that X16 could be involved in RNA processing correlating with cellular proliferation.

Amino Acid Sequence↗
PubMed1991

The genes for a mouse hematopoietic differentiation marker called the heat-stable antigen.

We have isolated a murine cDNA by virtue of its expression in pre-B cell lines but not in plasmacytomas. In mouse, mRNA is detected by Northern blot analysis exclusively in hematopoietic tissues with the exception of brain. When expressed in bacteria, the encoded protein is specifically recognized by several antibodies against the murine hematopoietic differentiation marker called heat-stable antigen (HSA). In contrast to previous speculations, these results suggest that the antigenic determinant recognized by anti-HSA antibodies is proteinaceous. The cDNA sequence is essentially identical to a mouse HSA cDNA recently published (Kay et al., J. Immunol. 1990. 145: 1952). Three HSA genes were isolated, one of which corresponds to the isolated cDNA. The other two appear to be intronless retroposons which, despite numerous sequence changes, maintain an open reading frame. One of these intronless genes could code for an alternative form of HSA with a transmembrane domain and a cytoplasmic tail not encoded by the intron-containing gene. This gene could be expressed, based on sequence comparisons of the three genes. However, using polymerase chain reaction amplification of first strand cDNA from various cell lines and adult mouse tissues, we could detect expression only of the intron-containing gene.

Animals↗
PubMed1986

E alpha u and E beta u chain association: where lies the anomaly?

H-2u haplotype mice are unique among all E alpha+ strains because they do not provide in heterozygotes an E alpha chain that interacts with E betak,s,etc. sufficiently well to allow certain E-restricted immune responses. As a first step in understanding this peculiarity, we have sequenced E alpha u and E beta u cDNA and compared the derived amino acid sequences with those of previously analyzed alleles. Although no glaring structural abnormalities were found, we have identified some u-specific residues and suggest which are the most likely to provoke a pairing anomaly.

Alleles↗
PubMed1985

Inbred and wild mice carry identical deletions in their E alpha MHC genes.

Several inbred strains and a certain percentage of wild mice bear a deletion in the E alpha gene of the mouse major histocompatibility complex (H-2). This mutation prevents transcription of the E alpha gene and hence functional expression of the E alpha E beta dimer on the cell surface. Two strains were selected for a more precise localization of this deletion. BALB.B is a congenic line carrying the H-2b haplotype on the BALB/c background. CRO435 is an outbred stock derived from a wild mouse captured near Cairo, Egypt; it carries the H-2w37 haplotype including a null Ew28 alpha allele, as well as semi-lethal mutations in the H-2 linked t complex (tTuw7). From these two strains, we have isolated genomic clones that contain fragments spanning the E alpha deletion, and have sequenced the breakpoint region. The deletions in the two strains are identical, spanning 627 bp which include the promoter region and the signal peptide exon of the E alpha gene. Limited sequence comparison suggests that the Eb alpha allele of BALB.B is more closely related to the Ew28 alpha allele of CRO435 than both of these are to an E alpha-expressor allele, Ed alpha. It is therefore likely that the Eo deletions in the various inbred strains and wild mice are of the same origin, and we propose that they have been disseminated throughout the mouse population because of linkage to the t complex.

Animals↗