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A series of sixty hitherto unknown cubic lead and tin halide perovskites with the saturated heterocyclic cations (CH 2) n PH 2 + and (CH 2) n SH+, (n = 2–6) is modeled using periodic DFT approach for the first time. We find that the proposed species are direct bandgap semiconductors with the lattice constants varying from 6.01 Å to 7.71 Å and absorption wavelengths covering the energy range [1.39–5.26] eV. The estimated masses and velocities of charge carriers amount to ∼ m e and ∼105 m/s, respectively. Electronic properties of the proposed compounds are compared with that of the previously described lead and tin halide perovskites with the saturated heterocyclic cations (CH 2) n NH 2 + and (CH 2) n OH+, (n = 2–6). The proposed compounds considerably expand the family of photoactive hybrid metal-halide perovskites. • Novel HOIPs ABX 3 [A=(CH 2) n PH 2 , (CH 2) n SH; n = 2–6; B=Pb, Sn; X = Cl, Br, I] are proposed. • The computed crystal lattice parameters correlate with the sizes of the constituent ions. • The principal direct electronic bandgaps vary from 1.39 eV to 5.26 eV. • The velocities and masses of charge carriers are of the order of 105 m/s and m 0 , respectively. [ABSTRACT FROM AUTHOR]

Summary The linear ubiquitin chain assembly complex (LUBAC) participates in inflammatory and oncogenic signaling by conjugating linear ubiquitin chains to target proteins. LUBAC consists of the catalytic HOIP subunit and two accessory subunits, HOIL-1L and SHARPIN. Interactions between the ubiquitin-associated (UBA) domains of HOIP and the ubiquitin-like (UBL) domains of two accessory subunits are involved in LUBAC stabilization, but the precise molecular mechanisms underlying the formation of stable trimeric LUBAC remain elusive. We solved the co-crystal structure of the binding regions of the trimeric LUBAC complex and found that LUBAC-tethering motifs (LTMs) located N terminally to the UBL domains of HOIL-1L and SHARPIN heterodimerize and fold into a single globular domain. This interaction is resistant to dissociation and plays a critical role in stabilizing trimeric LUBAC. Inhibition of LTM-mediated HOIL-1L/SHARPIN dimerization profoundly attenuated the function of LUBAC, suggesting LTM as a superior target of LUBAC destabilization for anticancer therapeutics. [ABSTRACT FROM AUTHOR]

Summary The linear ubiquitin chain assembly complex (LUBAC) is the sole identified E3 ligase complex that catalyzes the formation of linear ubiquitin chain, and it is composed of HOIP, HOIL-1L, and SHARPIN. The E3 activity of HOIP can be effectively activated by HOIL-1L or SHARPIN, deficiency of which leads to severe immune system disorders. However, the underlying mechanism governing the HOIP-SHARPIN interaction and the SHARPIN-mediated activation of HOIP remains elusive. Here, we biochemically and structurally demonstrate that the UBL domain of SHARPIN specifically binds to the UBA domain of HOIP and thereby associates with and activates HOIP. We further uncover that SHARPIN and HOIL-1L can separately or synergistically bind to distinct sites of HOIP UBA with induced allosteric effects and thereby facilitate the E2 loading of HOIP for its activation. Thus, our findings provide mechanistic insights into the assembly and activation of LUBAC. [ABSTRACT FROM AUTHOR]

We present DFT study on a series of sixty hypothetical lead and tin halide perovskites containing known saturated heterocyclic cations (CH 2 ) n NH 2 + and (CH 2 ) n OH + , (n = 2–6). The calculations are performed using cubic crystal lattice symmetry constraint. According to them, the proposed compounds are analogs of the known photoactive HOIPs. Size of the organic cations determines structural, electronic, and optical properties of the species. Their lattice parameters vary from 5.96 Å to 7.71 Å, while the absorption wavelengths spread over the energy range of [1.37–5.39] eV. The estimated velocities of charge carriers amount to ∼10 5 m/s, whereas their masses are of the order of the free electron mass. Based on the obtained results we conclude that these perovskites may find applications in photovoltaics. [ABSTRACT FROM AUTHOR]

Ubiquitination is a post-translational modification that creates versatility in cell signalling, in part because eight biochemically different inter-ubiquitin linkages can be formed through the seven internal lysine residues of ubiquitin or its amino-terminal methionine. The latter, referred to as linear or M1 linkage, is created by the linear ubiquitin chain assembly complex (LUBAC). Previously, K63 linkages were thought to be exclusively responsible for ubiquitin-mediated nondegradative functions. It now emerges, however, that M1 ubiquitination is crucial in various pathways, and that generation of a physiological signalling output requires cooperation between different ubiquitin linkage types. Here, we review the currently known functions of LUBAC and M1 ubiquitination, discuss promising future research directions into their functions, and how this may reveal novel therapeutic opportunities for diseases with perturbed linear ubiquitination. [ABSTRACT FROM AUTHOR]