Reterenees.~lb Stra ci:Nontopolugical solitons are stable hounu state solutions whose boundary condition at infinity is the same as that for the phssical vacuum state. They exist in classical, as well as quantum mechanical, field theories.. These solutmoits in ans space-dimension are rcs iewed. We also discuss their applications to Bose liquid, hadron structures and soliton stars, 'Ibis research ssas supported in part by the US Department of Energs f)37(f-1S73:92/$lS.0() © 1992 Elsevier Science Publishers B.V. All rights reserved 253 2~4 1'. I). /,i'i' said I . /'any' , Nontopologu al so/ito,p rocess. Some general discussions are given in section 3. 1, stability under small perturbations is shown in section 3.2, and quantization in section 3.3.It is generally believed that QCD is the correct theory for the strong interaction and that eventually the detailed hadronic structure will he calculated from QCD. In the high energy region, because of asymptotic freedom, perturbation expansion is valid. This enables us to deduce many parameters for the quarks from high energy experiments. But in the low energy region. where it is of importance to the hadronic structure, the theory cannot be solved perturbatively. and nonperturhative effects dominate. The origin of quark confinement remains a major theoretical difficulty. For practical calculations. phenomenological models have been built to take into account some of the nonperturbative effects. SO that the rest of the theory can be solved by a perturbative method. As an application of nontopological solitons, section 5 discusses the Friedberg-Lee model. There are two very good reviews on this model and its variations. One is the volume "Nontopological Solitons" by Wilets [20], the other is a review article by Birse 1211. Here we will give a summary of major results.Another application of nontopological solitons is in exotic stellar structures, called soliton stars [24-27] to be discussed in section 6. Stable cold stellar configurations have been found which can have masses up to that of a galaxy. Soliton stars can he made either of boson fields or fermion fields. Their characteristics depend sensitively on nonlinear couplings. These stellar configurations all have energies lower than the corresponding free particle (plane wave) solution for any given particle number; consequently. soliton stars are prevented from decaying into free particles.. When a soliton star exceeds a certain critical mass, it collapses into a black hole. Because the mechanism for stability is quite different between soliton stars and ordinary stars, the soliton stars can have very different critical masses [7, 8,24,28] from the usual Oppenheimer-Volkov [29] type limit.Recently, the nontopological soliton has been extended to the study of the Bose liquid [30]. The liquid-gas phase transition can be formulated in terms of the spontaneous symmetry breaking of translational invariance in the canonical ensemble, while the Bose-Einstein transition is due to the breaking of the phase symmetry of the complex...

SUMMARY Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes (“spermatoproteasomes”) contain a spermatid/sperm-specific α-subunit α4s/PSMA8 and/or the catalytic β-subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks, and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis.

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Gene fusions and their products (RNA and protein) were once thought to be unique features to cancer. However, chimeric RNAs can also be found in normal cells. Here, we performed, curated and analyzed nearly 300 RNA-Seq libraries covering 30 different non-neoplastic human tissues and cells as well as 15 mouse tissues. A large number of fusion transcripts were found. Most fusions were detected only once, while 291 were seen in more than one sample. We focused on the recurrent fusions and performed RNA and protein level validations on a subset. We characterized these fusions based on various features of the fusions, and their parental genes. They tend to be expressed at higher levels relative to their parental genes than the non-recurrent ones. Over half of the recurrent fusions involve neighboring genes transcribing in the same direction. A few sequence motifs were found enriched close to the fusion junction sites. We performed functional analyses on a few widely expressed fusions, and found that silencing them resulted in dramatic reduction in normal cell growth and/or motility. Most chimeras use canonical splicing sites, thus are likely products of ‘intergenic splicing’. We also explored the implications of these non-pathological fusions in cancer and in evolution.