Empirical investigation of extreme single-particle behavior of nuclear quadrupole moments in highly collective A∼150 superdeformed bands

The intrinsic quadrupole moment Q0 of superdeformed rotational bands in A∼150 nuclei depends on the associated single-particle configuration. We have derived an empirical formula based on the additivity of effective quadrupole moments of single-particle orbitals that describes existing measurements from 142Sm to 152Dy. To further test the formula, the predicted Q0 moments for two superdeformed bands in 146Gd of 14.05eb were confronted with a new measurement yielding 13.9±0.4eb and 13.9 ± 0.3eb, respectively. This excellent agreement provides empirical evidence of extreme single-particle behavior in highly deformed, collective systems

DDX3 depletion represses translation of mRNAs with complex 5' UTRs

DDX3 is an RNA chaperone of the DEAD-box family that regulates translation. Ded1, the yeast ortholog of DDX3, is a global regulator of translation, whereas DDX3 is thought to preferentially affect a subset of mRNAs. However, the set of mRNAs that are regulated by DDX3 are unknown, along with the relationship between DDX3 binding and activity. Here, we use ribosome profiling, RNA-seq, and PAR-CLIP to define the set of mRNAs that are regulated by DDX3 in human cells. We find that while DDX3 binds highly expressed mRNAs, depletion of DDX3 particularly affects the translation of a small subset of the transcriptome. We further find that DDX3 binds a site on helix 16 of the human ribosomal rRNA, placing it immediately adjacent to the mRNA entry channel. Translation changes caused by depleting DDX3 levels or expressing an inactive point mutation are different, consistent with different association of these genetic variant types with disease. Taken together, this work defines the subset of the transcriptome that is responsive to DDX3 inhibition, with relevance for basic biology and disease states where DDX3 is altered