Anti-LYAR monoclonal antibody Made to order

Mammalian spermatogenesis is a complex process involving an intrinsic genetic program of germ cell-specific and -predominant genes. In the present study, we analyzed the Ly-1 reactive clone (Lyar) gene in the mouse. Lyar, which is known to be expressed abundantly in the testis, encodes a nucleolar protein that contains a LYAR-type C2HC zinc finger motif and three nuclear localization signals. We herein confirmed that Lyar is expressed predominantly in the testis, and further showed that this expression is specific to germ cells. Protein analyses with an anti-LYAR antibody demonstrated that the LYAR protein is present in spermatocytes and spermatids, but not in sperm. To assess the functional role of LYAR in vivo, we used a gene-trap mutagenesis approach to establish a LYAR-null mouse model. Lyar mutant mice were born live and developed normally. Male mutant mice lacking LYAR were fully fertile and showed intact spermatogenesis. Taken together, our results demonstrate that LYAR is strongly preferred in male germ cells, but has a dispensable role in spermatogenesis and fertility.

Recent studies have identified and characterized a novel putative transcriptional repressor site in a 5' untranslated region of the A gamma-globin gene that interacts with the Ly-1 antibody reactive clone (LYAR) protein. LYAR binds the 5'-GGTTAT-3' site of the A gamma-globin gene, and this molecular interaction causes repression of gene transcription. In beta-thalassemia patients, a polymorphism has been demonstrated (the rs368698783 G>A polymorphism) within the 5'-GGTTAT-3' LYAR-binding site of the A gamma-globin gene. The major results gathered from surface plasmon resonance based biospecific interaction analysis (SPR-BIA) studies (using crude nuclear extracts, LYAR-enriched lysates, and recombinant LYAR) support the concept that the rs368698783 G>A polymorphism of the A gamma-globin gene attenuates the efficiency of LYAR binding to the LYAR-binding site. This conclusion was fully confirmed by a molecular docking analysis. This might lead to a very important difference in erythroid cells from beta-thalassemia patients in respect to basal and induced levels of production of fetal hemoglobin. The novelty of the reported SPR-BIA method is that it allows the characterization and validation of the altered binding of a key nuclear factor (LYAR) to mutated LYAR-binding sites. These results, in addition to theoretical implications, should be considered of interest in applied pharmacology studies as a basis for the screening of drugs able to inhibit LYAR-DNA interactions. This might lead to the identification of molecules facilitating induced increase of gamma-globin gene expression and fetal hemoglobin production in erythroid cells, which is associated with possible reduction of the clinical severity of the beta-thalassemia phenotype.