Mosquito Olfactory Response Ensemble: a curated database of behavioral and electrophysiological responses enables pattern discovery

Many experimental studies have examined behavioral and electrophysiological responses of mosquitoes to odors. However, the differences across studies in data collection, processing, and reporting make it difficult to perform large-scale analyses combining data from multiple studies. Here we extract and standardize data for 12 mosquito species, along with Drosophila melanogaster for comparison, from over 170 studies and curate the Mosquito Olfactory Response Ensemble (MORE), publicly available at https://neuralsystems.github.io/MORE. We demonstrate the ability of MORE in generating biological insights by finding patterns across studies. Our analyses reveal that ORs are tuned to specific ranges of several physicochemical properties of odorants; the empty-neuron recording technique for measuring OR responses is more sensitive than the Xenopus oocyte technique; there are systematic differences in the behavioral preferences reported by different types of assays; and odorants tend to become less attractive or more aversive at higher concentrations.

Aquaporins in GtoPdb v.2021.3

Aquaporins and aquaglyceroporins are membrane channels that allow the permeation of water and certain other small solutes across the cell membrane, or in the case of AQP6, AQP11 and AQP12A, intracellular membranes, such as vesicles and the endoplasmic reticulum membrane [16]. Since the isolation and cloning of the first aquaporin (AQP1) [20], 12 additional mammalian members of the family have been identified, although little is known about the functional properties of one of these (AQP12A; Q8IXF9) and it is thus not tabulated. The other 12 aquaporins can be broadly divided into three families: orthodox aquaporins (AQP0,-1,-2,-4,-5, -6 and -8) permeable mainly to water, but for some additional solutes [4]; aquaglyceroporins (AQP3,-7 -9 and -10), additionally permeable to glycerol and for some isoforms urea [14], and superaquaporins (AQP11 and 12) located within cells [12]. Some aquaporins also conduct ammonia and/or H2O2 giving rise to the terms 'ammoniaporins' ('aquaammoniaporins') and 'peroxiporins', respectively. Aquaporins are impermeable to protons and other inorganic and organic cations, with the possible exception of AQP1, although this is controversial [14]. One or more members of this family of proteins have been found to be expressed in almost all tissues of the body [reviewed in Yang (2017) [26]]. AQPs are involved in numerous processes that include systemic water homeostasis, adipocyte metabolism, brain oedema, cell migration and fluid secretion by epithelia. Loss of function mutations of some human AQPs, or their disruption by autoantibodies further underscore their importance [reviewed by Verkman et al. (2014) [23], Kitchen et al. (2105) [14]]. Functional AQPs exist as homotetramers that are the water conducting units wherein individual AQP subunits (each a protomer) have six TM helices and two half helices that constitute a seventh 'pseudotransmembrane domain' that surrounds a narrow water conducting channel [16]. In addition to the four pores contributed by the protomers, an additional hydrophobic pore exists within the center of the complex [16] that may mediate the transport through AQP1. Although numerous small molecule inhibitors of aquaporins, particularly APQ1, have been reported primarily from Xenopus oocyte swelling assays, the activity of most has subsequently been disputed upon retesting using assays of water transport that are less prone to various artifacts [5] and they are therefore excluded from the tables [see Tradtrantip et al. (2017) [22] for a review].

A Novel Efficient L-Lysine Exporter Identified by Functional Metagenomics

Lack of active export system often limits the industrial bio-based production processes accumulating the intracellular product and hence complexing the purification steps. L-lysine, an essential amino acid, is produced biologically in quantities exceeding two million tons per year; yet, L-lysine production is challenged by efficient export system at high titres during fermentation. To address this issue, new exporter candidates for efficient efflux of L-lysine are needed. Using metagenomic functional selection, we identified 58 genes encoded on 28 unique metagenomic fragments from cow gut microbiome library that improved L-lysine tolerance. These genes include a novel putative L-lysine transporter, belonging to a previously uncharacterized EamA superfamily. Characterization using Xenopus oocyte expression system as well as an Escherichia coli host demonstrates activity as a L-lysine transporter. This novel exporter improved L-lysine tolerance in E. coli by 40% and enhanced the specific productivity of L-lysine in an industrial Corynebacterium glutamicum strain by 12%. Our approach allows the sequence-independent discovery of novel exporters and can be deployed to increase titres and productivity of toxicity-limited bioprocesses.

Novel Mutations in the TMPRSS3 Gene May Contribute to Taiwanese Patients with Nonsyndromic Hearing Loss

A previous study indicated that mutations in the transmembrane protease serine 3 (TMPRSS3) gene, which encodes a transmembrane serine protease, cause nonsyndromic hearing loss (NSHL). This was the first description of a serine protease involved in hearing loss (HL). In Taiwan, however, data on the TMPRSS3 gene’s association with NSHL is still insufficient. In this study, we described 10 mutations of TMPRSS3 genes found in 14 patients after screening 230 children with NSHL. The prevalence of the TMPRSS3 mutation appeared to be 6.09% (14/230). Of the 10 mutations, three were missense mutations: c.239G>A (p.R80H), c.551T>C (p.L184S), and 1253C>T (p.A418V); three were silent mutations, and four were mutations in introns. To determine the functional importance of TMPRSS3 mutations, we constructed plasmids carrying TMPRSS3 mutations of p.R80H, p.L184S, and p.A418V. TMPRSS3 function can be examined by secretory genetic assay for site-specific proteolysis (sGASP) and Xenopus oocyte expression system. Our results showed that p.R80H, p.L184S, and p.A418V TMPRSS3 mutations gave ratios of 19.4%, 13.2%, and 27.6%, respectively, via the sGASP system. Moreover, these three TMPRSS3 mutations failed to activate the epithelial sodium channel (ENaC) in the Xenopus oocyte expression system. These results indicate that the p.R80H, p.L184S, and p.A418V missense mutations of TMPRSS3 resulted in greatly diminishing the proteolytic activity of TMPRSS3. Our study provides information for understanding the importance of TMPRSS3 in the NSHL of Taiwanese children and provides a novel molecular explanation for the role of TMPRSS3 in HL.