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Introduction and Methods: We report two series of individuals with DDX3X variations, one (48 individuals) from physicians and one (44 individuals) from caregivers., Results: These two series include several symptoms in common, with fairly similar distribution, which suggests that caregivers' data are close to physicians' data. For example, both series identified early childhood symptoms that were not previously described: feeding difficulties, mean walking age, and age at first words., Discussion: Each of the two datasets provides complementary knowledge. We confirmed that symptoms are similar to those in the literature and provides more details on feeding difficulties. Caregivers considered that the symptom attention-deficit/hyperactivity disorder were most worrisome. Both series also reported sleep disturbance. Recently, anxiety has been reported in individuals with DDX3X variants. We strongly suggest that attention-deficit/hyperactivity disorder, anxiety, and sleep disorders need to be treated., (© 2024 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Members of the group of 7-kDa cold-shock proteins (CSPs) are the proteins with the highest level of induction upon cold shock in the lactic acid bacterium Lactococcus lactis MG1363. By using double-crossover recombination, two L. lactis strains were generated in which genes encoding CSPs are disrupted: L. lactis NZ9000 Delta AB lacks the tandemly orientated cspA and cspB genes, and NZ9000 Delta ABE lacks cspA, cspB, and cspE. Both strains showed no differences in growth at normal and at low temperatures compared to that of the wild-type strain, L. lactis NZ9000. Two-dimensional gel electrophoresis showed that upon disruption of the cspAB genes, the production of remaining CspE at low temperature increased, and upon disruption of cspA, cspB, and cspE, the production of CspD at normal growth temperatures increased. Northern blot analysis showed that control is most likely at the transcriptional level. Furthermore, it was established by a proteomics approach that some (non-7-kDa) cold-induced proteins (CIPs) are not cold induced in the csp-lacking strains, among others the histon-like protein HslA and the signal transduction protein LlrC. This supports earlier observations (J. A. Wouters, M. Mailhes, F. M. Rombouts, W. M. De Vos, O. P. Kuipers, and T. Abee, Appl. Environ. Microbiol. 66:3756-3763, 2000). that the CSPs of L. lactis might be directly involved in the production of some CIPs upon low-temperature exposure. Remarkably, the adaptive response to freezing by prior exposure to 10 degrees C was significantly reduced in strain NZ9000 Delta ABE but not in strain NZ9000 Delta AB compared to results with wild-type strain NZ9000, indicating a notable involvement of CspE in cryoprotection.

The regulatory functions of the leader region preceding the Lactococcus lactis trp operon have been studied by mutagenesis analysis. This leader presents striking similarity to 'T-box' leaders found upstream of many Gram-positive aminoacyl-tRNA synthetase genes and some amino acid biosynthesis operons, which are controlled by antitermination through interaction of the leader transcript with cognate uncharged tRNA. A region of the L. lactis leader transcript also contains a series of (G/U) AG repeats which, in Bacillus, are involved in the binding of the trp RNA-binding protein (TRAP) which controls trp transcription. A screen was developed for the isolation of regulatory mutants affected in the leader region. All spontaneous mutants contained deletions; point mutations were only obtained after UV-induced mutagenesis. All mutations affected the putative transcription terminator upstream of the trp operon, demonstrating that trp is indeed controlled by transcription antitermination.