Biomedical subjects

M Ruggiu

Publications and source records attributed to M Ruggiu.

20 records · Page 2Linked to original sources

PubMed1994

Two homologous genes, originated by duplication, encode the human hnRNP proteins A2 and A1.

Heterogeneous nuclear ribonucleoprotein (hnRNP) A2 belongs, with A1, B1 and B2, to the basic protein subset of the hnRNP complex in mammalian cells. All these proteins share a modular structure consisting of two conserved RNA binding domains linked to less conserved Gly-rich domains (2xRBD-Gly). In the framework of our studies on the genetic basis of hnRNP proteins structure and diversity we have isolated and sequenced the A2 gene and compared it to the previously described A1 gene. The A2 gene, which exists in a single copy on Ch. 7 band p15, is split in 12 exons including an alternatively spliced 36 nt mini exon specific for the human hnRNP protein B1. In this work we show that the intron/exon organisation of the A2 gene is identical to that of the A1 gene over the entire length, indicating a common origin by gene duplication. Moreover the comparison of corresponding exons evidences significant conservation also in the apparently divergent Gly-rich domains that could define previously unenvisaged structural and/or functional motifs. The A2 gene promoter is also analysed in comparison to that of the A1 gene.

Amino Acid Sequence↗

PubMedDate not supplied

Dynamic subcellular distribution of the DAZL protein is confined to primate male germ cells.

We have examined the location of the DAZL protein in fetal and adult rodents and human specimens and found that there is a shift from a predominantly nuclear to a predominantly cytoplasmic distribution of the protein in human testis. In rat testis and human ovary, however, the protein is predominantly, if not exclusively, cytoplasmic throughout germ cell development. One possible explanation for this could be that the DAZ protein is responsible for the nuclear localization of DAZL in human males. We have tested this hypothesis by examining the testis of marmosets, which lack the Daz genes and have found that the DAZL protein is both nuclear and cytoplasmic in spermatogonia, and by analyzing testis sections from DAZ-deleted patients in whom the cytoplasmic location of DAZL is evident in remaining germ cells. Transfection experiments indicate that the differences in DAZL expression between rodents and humans are not caused by the amino acid differences between the 2 proteins, and that DAZL is a cytoplasmic protein per se. Variations in location seem to be independent of the presence of the DAZ protein are species specific and, as in Drosophila, may not have great functional significance.

Adult↗