After activation, Itk phosphorylates and activates phospholipase C-gamma 1 (PLC-gamma 1), leading to production of two second messengers, DAG and IP(3). We have previously shown that phosphorylation of PLC-gamma 1 by Itk requires a direct, phosphotyrosine-independent interaction between the Src homology 2 (SH2) domain of PLC-gamma

Akt inhibitor 1 and the kinase domain of Itk. We now define this docking interface using a combination of mutagenesis and NMRspectroscopy and show that disruption of the Itk/PLC gamma 1 docking interaction attenuates T cell signaling. The binding surface on PLC gamma 1 that mediates recognition by Itk highlights a nonclassical binding activity of the well-studied SH2 domain providing further evidence that SH2 domains participate in important signaling interactions beyond recognition of phosphotyrosine.”
“Ribosome assembly selleck kinase inhibitor is a hierarchical process that involves pre-rRNA folding, modification, and cleavage and assembly of ribosomal proteins. In eukaryotes, this process requires a macromolecular complex comprising over 200 proteins and RNAs. Whereas the rRNA modification machinery is well-characterized, rRNA cleavage to release mature rRNAs is poorly understood, and in yeast, only 2 of 8 endonucleases have been identified. The essential and conserved ribosome assembly factor Nob1 has been suggested

to be the endonuclease responsible for generating the mature 3′-end of 18S rRNA by cleaving at site D. Here we provide evidence that recombinant Nob1 forms a tetramer that binds directly to pre-rRNA analogs containing cleavage site D. Analysis of Nob1′s affinity to a series of RNA truncations, as well as Nob1-dependent protections of pre-rRNA in vitro and in vivo demonstrate that Nob1′s binding site centers around the 3′-end of 18S rRNA, where our data also locate Nob1′s suggested active site. Thus, Nob1 is poised for cleavage at the 3′-end of 18S rRNA. Together with prior data, these results strongly implicate Nob1 in cleavage at site D. In addition, our

data provide evidence that the cleavage site at the 3′-end of 18S rRNA is single-stranded and not part of a duplex as commonly depicted. Using these results, selleck chemical we have built a model for Nob1′s interaction with preribosomes.”
“Although Mediterranean temporary pools are of great value for conservation, they are in rapid decline under the impact of various forms of anthropogenic pressure. Their disappearance from the landscape may result in a weakening of the biological connections between pools due to increasing isolation and the impoverishment of their communities. In Western Morocco (province of Benslimane), temporary pools have undergone severe regression over the past decades. The quantification of these losses and the impact on the richness of plant communities remain, however, unstudied.