In this paper we present results of a comprehensive analysis of the effect of heat shock at different stages of ontogenesis (adult stage, development of mushroom bodies and the central complex) on courtship behavior (latency, duration and efficacy of courtship), sound production (pulse interval, dispersion of interpulse interval, percentage of distorted pulses, the mean duration of the pulse samples), learning and memory formation compared with the content of LIMK1 isoforms in male Drosophila melanogaster with altered structure of the limk1 gene. The heat shock is shown to affect the behavior parameters and LIMK1 content in the analyzed strains of Drosophila. The most pronounced effect of the heat shock was observed at the stage of development of the central complex (CC). Heat shock at CC and adults restores the ability of learning and memory formation in the mutant strain agn ^ts3 that normally is unable to learn and form memory. Correlations between changes of content of LIMK1 isoforms and behavioral parameters due to heat shock have not been established.

Cancer cells tend to increase intracellular pH and, at the same time, are known to intensively produce and uptake polyamines such as spermine. Here, we show that various amines, including biogenic polyamines, boost the activity of proteasomes in a dose-dependent manner. Proteasome activity in the classical amine-containing buffers, such as 2-(N-morpholino)ethanesulfonic acid (MES), Tris, (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), glycylglycine, bis-Tris propane, and bicine, has a skewed distribution with a maximum at pH of 7.0–8.0. The activity of proteasomes in buffers containing imidazole and bis-Tris is maintained almost on the same level, in the pH range of 6.5–8.5. The third type of activation is observed in buffers based on the amino acids arginine and ornithine, as well as the natural polyamines spermine and spermidine. Proteasome activity in these buffers is dramatically increased at pH values greater than 7.5. Anionic buffers such as phosphate or carbonate, in contrast, inhibit proteasome activity during alkalization. Importantly, supplementation of a carbonate–phosphate buffer with spermine counteracts carbonate-driven proteasome stalling in alkaline conditions, predicting an additional physiological role of polyamines in maintaining the metabolism and survival of cancer cells.

Effect of LIM kin ase 1 is oform ratio on Drosophil a mel anogaster courtship behavior: a complex approach

We have shown previously that the polymorphic structure of the limk1 gene in Drosophila leads to changes in LIMK1 content and to defects in courtship behavior, sound production, and learning/memory. The results of the present study of three wild-type strains and mutant agn ^ts3 with altered limk1 structure demonstrate that long-term memory is normal in Canton-S and Oregon-R but is impaired in Berlin and drastically suppressed in agn ^ts3 . This temperature-sensitive mutant carries the S-element from the Tc1/mariner family insertion near the dlimk1 3′-UTR and, compared to Canton-S, has a reverse pCREB distribution in adult neuromuscular junctions (NMJ) of the second dorsal imago nerve before and after learning. Moreover, only agn ^ts3 demonstrates amyloid-like aggregate formation in NMJ. This suggests that this impedes pCREb transport and thereby impairs the formation of short- and long-term memory.

Ubiquitination is an evolutionary, ancient system of post-translational modification of proteins that occurs through a cascade involving ubiquitin activation, transfer, and conjugation. The maturation of this system has followed two main pathways. The first is the conservation of a universal structural fold of ubiquitin and ubiquitin-like proteins, which are present in both Archaea and Bacteria, as well as in multicellular Eukaryotes. The second is the rise of the complexity of the superfamily of ligases, which conjugate ubiquitin-like proteins to substrates, in terms of an increase in the number of enzyme variants, greater variation in structural organization, and the diversification of their catalytic domains. Here, we examine the diversity of the ubiquitination system among different organisms, assessing the variety and conservation of the key domains of the ubiquitination enzymes and ubiquitin itself. Our data show that E2 ubiquitin-conjugating enzymes of metazoan phyla are highly conservative, whereas the homology of E3 ubiquitin ligases with human orthologues gradually decreases depending on “molecular clock” timing and evolutionary distance. Surprisingly, Chordata and Echinodermata, which diverged over 0.5 billion years ago during the Cambrian explosion, share almost the same homology with humans in the amino acid sequences of E3 ligases but not in their adaptor proteins. These observations may suggest that, firstly, the E2 superfamily already existed in its current form in the last common metazoan ancestor and was generally not affected by purifying selection in metazoans. Secondly, it may indicate convergent evolution of the ubiquitination system and highlight E3 adaptor proteins as the “upper deck” of the ubiquitination system, which plays a crucial role in chordate evolution.

LIM-kinase 1 is a key enzyme of actin remodeling, which is necessary for synaptic plasticity during learning and memory formation. The deletion of the limk1 leads to the development of Williams’s syndrome accompanied by cognitive impairments and motor dysfunction, which is referred to as cytoskeleton diseases, cofilin pathologies. Cofilin pathologies are characterized by the formation of cofilin-actin complexes in neurons, which disrupt vesicular transport and identify early stages of dementia. In the present article, we briefly reviewed the data on the role of the LIMK1 functioning in communicative sound production during courtship behavior, learning acquisition, and memory formation.