Missense variant interaction scanning reveals a critical role of the FERM domain for tumor suppressor protein NF2 conformation and function.

NF2 (moesin-ezrin-radixin-like [MERLIN] tumor suppressor) is frequently inactivated in cancer, where its NF2 tumor suppressor functionality is tightly coupled to protein conformation. How NF2 conformation is regulated and how NF2 conformation influences tumor suppressor activity is a largely open question. Here, we systematically characterized three NF2 conformation-dependent protein interactions utilizing deep mutational scanning interaction perturbation analyses.

Interaction modulation through arrays of clustered methyl-arginine protein modifications.

Systematic analysis of human arginine methylation identifies two distinct signaling modes; either isolated modifications akin to canonical post-translational modification regulation, or clustered arrays within disordered protein sequence. Hundreds of proteins contain these methyl-arginine arrays and are more prone to accumulate mutations and more tightly expression-regulated than dispersed methylation targets. Arginines within an array in the highly methylated RNA-binding protein synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP) were experimentally shown to function in concert, providing a tunable protein interaction interface.

Augmentation of phosphate-induced osteo-/chondrogenic transformation of vascular smooth muscle cells by homoarginine.

Aims: Reduced homoarginine plasma levels are associated with unfavourable cardiovascular outcome in chronic kidney disease (CKD). Cardiovascular events in CKD are fostered by vascular calcification, an active process promoted by hyperphosphatemia and involving osteo-/chondrogenic transformation of vascular smooth muscle cells (VSMCs). The present study explored the effect of homoarginine on phosphate-induced osteo-/chondrogenic signalling and vascular calcification.

Selective Irreversible Inhibition of Neuronal and Inducible Nitric-oxide Synthase in the Combined Presence of Hydrogen Sulfide and Nitric Oxide.

Citrulline formation by both human neuronal nitric-oxide synthase (nNOS) and mouse macrophage inducible NOS was inhibited by the hydrogen sulfide (H2S) donor Na2S with IC50 values of ∼2.4·10(-5) and ∼7.9·10(-5) m, respectively, whereas human endothelial NOS was hardly affected at all.

Aerobic nitric oxide-induced thiol nitrosation in the presence and absence of magnesium cations.

Although different routes for the S-nitrosation of cysteinyl residues have been proposed, the main in vivo pathway is unknown. We recently demonstrated that direct (as opposed to autoxidation-mediated) aerobic nitrosation of glutathione is surprisingly efficient, especially in the presence of Mg(2+). In the present study we investigated this reaction in greater detail.

Interaction between neuronal nitric-oxide synthase and tetrahydrobiopterin revisited: studies on the nature and mechanism of tight pterin binding.

Recombinant neuronal nitric-oxide synthase (nNOS) expressed in baculovirus-infected Sf9 cells contains approximately 1 equiv of tightly bound tetrahydrobiopterin (BH4) per dimer and binds a second equivalent with a dissociation constant in the 10(-7)-10(-6) M range. Less is known about the pterin-binding properties of nNOS originating from expression systems such as Escherichia coli that do not produce BH4. We determined the binding properties of E.