SARS-Cov-2 In der Zuschrift aus S. 21830 berichten Xinjing Tang et al. über die effiziente Hemmung von SARS-CoV-2 mit chimären Antisense-Oligonukleotiden durch Aktivierung RNase L.

Self-incompatibility (SI) is a genetic mechanism that allows flowering plants to identify and block fertilization by self-pollen. In the Solanaceae, SI is controlled by a multiallelic S-locus encoding both S-RNases and F-box proteins as female and male determinants, respectively. S-RNase activity is essential for pollen rejection, and a minimum threshold value of S-RNases in the style is also r...

Gametophytic self-incompatibility (GSI) is controlled by a complex S locus containing the pistil determinant S-RNase and pollen determinant SFB/SLF. Tight linkage of the pistil and pollen determinants is necessary to guarantee the self-incompatibility (SI) function. However, multiple probable pollen determinants of apple and Japanese pear, SFBBs (S locus F-box brothers), exist in each S haploty...

Self-incompatibility (SI) is widespread in the angiosperms, but identifying the biochemical components of SI mechanisms has proven to be difficult in most lineages. Coffea (coffee; Rubiaceae) is a genus of old-world tropical understory trees in which the vast majority of diploid species utilize a mechanism of gametophytic self-incompatibility (GSI). The S-RNase GSI system was one of the first S...

The products of the S-locus expressed in female tissues of Nicotiana alata are ribonucleases (S-RNases). The arrest of growth of incompatible pollen tubes in styles may result from entry of the S-RNase into the pollen tube and degradation of pollen tube RNA. We investigated the action of isolated S-RNases on pollen tubes grown in vitro and found that S-RNase is taken up by the pollen without su...

S-RNase-based gametophytic self-incompatibility (GSI) has evolved once before the split of the Asteridae and Rosidae. This conclusion is based on the phylogenetic history of the S-RNase that determines pistil specificity. In Rosaceae, molecular characterizations of Prunus species, and species from the tribe Pyreae (i.e., Malus, Pyrus, Sorbus) revealed different numbers of genes determining S-po...

The S-peptide and S-protein fragments of ribonuclease S (RNase S, no EC no. assigned) have been immobilized onto separate Sepharose gels via a "leash" of polycytidylic acid substrate. Each of these gels releases its RNase fragment when treated with the complementary enzyme fragment or with RNase A (EC 3.1.27.5), and the released fragments recombine to give RNase S activity. Thus this system pro...

The amino-terminal 20 amino acids are required for microinjected ribonuclease A (RNase A) to be taken up by lysosomes and degraded at an enhanced rate during serum withdrawal. We used water-soluble carbodiimides to covalently attach the RNase S-peptide (residues 1-20) to [3H]RNase S-protein (residues 21-124) at unspecified locations. We then measured catabolism of the [3H]S-protein-S-peptide co...

Gametophytic self-incompatibility (GSI) allows plants to block fertilization by haploid pollen whose S-allele constitution matches one of the two S-alleles in the diploid styles. GSI in Solanum chacoense requires a stylar S-RNase, first secreted from cells of the transmitting tract then imported into incompatible (self) pollen tubes. However, the molecular mechanisms allowing compatible pollen ...

Recently, we have provided evidence that the polymorphic self-incompatibility (S) locus-encoded F-box (SLF) protein AhSLF-S(2) plays a role in mediating a selective S-RNase destruction during the self-incompatible response in Antirrhinum hispanicum. To investigate its role further, we first transformed a transformation-competent artificial chromosome clone (TAC26) containing both AhSLF-S(2) and...