Liprin-α-Mediated Assemblies and Their Roles in Synapse Formation

Brain’s functions, such as memory and learning, rely on synapses that are highly specialized cellular junctions connecting neurons. Functional synapses orchestrate the assembly of ion channels, receptors, enzymes, and scaffold proteins in both pre- and post-synapse. Liprin-α proteins are master scaffolds in synapses and coordinate various synaptic proteins to assemble large protein complexes. The functions of liprin-αs in synapse formation have been largely uncovered by genetic studies in diverse model systems. Recently, emerging structural and biochemical studies on liprin-α proteins and their binding partners begin to unveil the molecular basis of the synaptic assembly. This review summarizes the recent structural findings on liprin-αs, proposes the assembly mechanism of liprin-α-mediated complexes, and discusses the liprin-α-organized assemblies in the regulation of synapse formation and function.

Information processing in biological molecular machines

ABSTRACTBiological molecular machines are enzymes that simultaneously catalyze two processes, one donating free energy and second accepting it. Recent studies show that most native protein enzymes have a rich stochastic dynamics of conformational transitions which often manifests in fluctuating rates of the catalyzed processes and the presence of short-term memory resulting from the preference of certain conformations. For arbitrarily complex stochastic dynamics of protein machines, we proved the generalized fluctuation theorem predicting the possibility of reducing free energy dissipation at the expense of creating some information stored in memory. That this may be the case has been shown by interpreting results of computer simulations for a complex model network of stochastic transitions. The subject of the analysis was the time course of the catalyzed processes expressed by sequences of jumps at random moments of time. Since similar signals can be registered in the observation of real systems, all theses of the paper are open to experimental verification.STATEMENT OF SIGNIFICANCEThe transient utilization of memory for storing information turns out to be crucial for the movement of protein motors and the reason for most protein machines to operate as dimers or higher organized assemblies. From a broader physical point of view, the division of free energy into the operation and organization energies is worth emphasizing. Information can be assigned a physical meaning of a change in the value of both these functions of state.

9 Art. 8 GG: Freedom of Assembly

This chapter discusses the provisions of Art. 8 of the Grundgesetz (GG) with regard to the fundamental right of freedom of assembly. It begins by reviewing the Federal Constitutional Court's first landmark decision on freedom of assembly in 1985, in which it emphasised the importance of the process of political will formation and the right of citizens to free assembly through demonstrations, noting that ‘the unhindered exercise of this freedom counteracts the consciousness of political powerlessness and dangerous tendencies of disgruntlement with the state and its institutions’. The chapter also examines the Court's jurisprudence concerning the scope of protection for the right of freedom of assembly, focussing on issues such as peacefulness in sit-in protests and the constitutionality of the registration requirement for rapidly organized assemblies. It concludes with an analysis of the question of interference with the right of freedom of assembly, along with the constitutional justification of such interferences.

Templated nanofiber synthesis via chemical vapor polymerization into liquid crystalline films

Extrusion, electrospinning, and microdrawing are widely used to create fibrous polymer mats, but these approaches offer limited access to oriented arrays of nanometer-scale fibers with controlled size, shape, and lateral organization. We show that chemical vapor polymerization can be performed on surfaces coated with thin films of liquid crystals to synthesize organized assemblies of end-attached polymer nanofibers. The process uses low concentrations of radical monomers formed initially in the vapor phase and then diffused into the liquid-crystal template. This minimizes monomer-induced changes to the liquid-crystal phase and enables access to nanofiber arrays with complex yet precisely defined structures and compositions. The nanofiber arrays permit tailoring of a wide range of functional properties, including adhesion that depends on nanofiber chirality.