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The green algae of the genus Ancylonema, which belong to the zygnematophytes, are prevalent colonizers of glaciers worldwide. They display a striking reddish-brown pigmentation in their natural environment, due to vacuolar compounds related to gallic acid. This pigmentation causes glacier darkening when these algae bloom, leading to increased melting rates. The Ancylonema species known so far are true psychrophiles, which hinders experimental work and limits our understanding of these algae. For instance, the biosynthesis, triggering factors, and biological function of Ancylonema's secondary pigments remain unknown. In this study, we introduce a mesophilic Ancylonema species, A. palustre sp. nov., from temperate moorlands. This species forms the sister lineage to all known psychrophilic strains. Despite its morphological similarity to the latter, it exhibits unique autecological and photophysiological characteristics. It allows us to describe vegetative and sexual cellular processes in great detail. We also conducted experimental tests for abiotic factors that induce the secondary pigments of zygnematophytes. We found that low nutrient conditions combined with ultraviolet B radiation result in vacuolar pigmentation, suggesting a sunscreen function. Our thriving, bacteria-free cultures of Ancylonema palustre will enable comparative genomic studies of mesophilic and extremophilic zygnematophytes. These studies may provide insights into how Ancylonema species colonized the world's glaciers., (© 2024 The Author(s). Environmental Microbiology published by John Wiley & Sons Ltd.)

Background: Ultrasound beam aberration correction is vital when focusing ultrasound through the skull bone in transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) applications. Current methods make transducer element phase adjustments to compensate for the variation in skull properties (shape, thickness, and acoustic properties), but do not account for variations in the internal brain anatomy., Purpose: Our objective is to investigate the effect of cerebrospinal fluid (CSF) and brain anatomy on beam focusing in tcMRgFUS treatments., Methods: Simulations were conducted with imaging data from 20 patients previously treated with focused ultrasound for disabling tremor. The Hybrid Angular Spectrum (HAS) method was used to test the effect of including cerebral spinal fluid (CSF) and brain anatomy in determining the element phases used for aberration correction and beam focusing. Computer tomography (CT) and magnetic resonance imaging (MRI) images from patient treatments were used to construct a segmented model of each patient's head. The segmented model for treatment simulation consisted of water, skin, fat, brain, CSF, diploë, and cortical bone. Transducer element phases used for treatment simulation were determined using time reversal from the desired focus, generating a set of phases assuming a homogeneous brain in the intracranial volume, and a second set of phases assigning CSF acoustic properties to regions of CSF. In addition, for three patients, the relative effect of separately including CSF speed of sound values compared to CSF attenuation values was found., Results: We found that including CSF acoustic properties (speed of sound and attenuation) during phase planning compared to phase correction without considering CSF increased the absorbed ultrasound power density ratios at the focus over a range of 1.06 to 1.29 (mean of 17% ± 6%) for 20 patients. Separately considering the CSF speed of sound and CSF attenuation showed that the increase was due almost entirely to including the CSF speed of sound; considering only the CSF attenuation had a negligible effect., Conclusions: Based on HAS simulations, treatment planning phase determination using morphologically realistic CSF and brain anatomy yielded an increase of up to 29% in the ultrasound focal absorbed power density. Future work will be required to validate the CSF simulations., (© 2023 American Association of Physicists in Medicine.)

The relative reinforcing value of food versus engagement in other behaviors may be related to the development of obesity, and interventions to reduce FRR may prevent the development of obesity. Our laboratory recently developed a paradigm to measure the reinforcing value of food versus an alternative behavior (i.e., playing with bubbles) in infants using a computerized laboratory task, during which infants press a button to earn reinforcers following a progressive ratio schedule of reinforcement. The primary purpose of this study was to examine the short-term (within 2 weeks) repeatability of this measure, specifically the outcome of infant food reinforcing ratio (FRR), or how hard infants will work for food relative to the alternative. The secondary aim was to examine whether infant age and temperament dimensions related to novelty responsiveness (high intensity pleasure and approach) moderated the repeatability of FRR. Thirty-seven infants aged 9-18 months completed this study. Repeated measures analysis of variance (ANOVA) showed no differences between time 1 and time 2 in responding for food (F = 0.463, p = 0.501), bubbles (F = 1.793, p = 0.189), or overall FRR (F = 0.797, p = 0.378). Regression models showed the association between BUB P max at time 1 and time 2 were moderated by infant age (p = 0.04), with greater repeatability in older infants. Linear regression models also demonstrated that the infant temperamental dimension of high intensity pleasure significantly predicted BUB P max at time 1 (β = 2.89, p = 0.01), but not at time 2. Overall, our findings support the repeatability of this measure for food portion of the reinforcement task, but demonstrated that the measure of non-food portion of the task required modification, in particular among children younger than 13 months old., (Published by Elsevier Ltd.)

Proximal spinal muscular atrophy (SMA), one of the most common genetic causes of infant death, results from the selective loss of motor neurons in the spinal cord. SMA is a consequence of low levels of survival motor neuron (SMN) protein. In humans, the SMN gene is duplicated; SMA results from the loss of SMN1 but SMN2 remains intact. SMA severity is related to the copy number of SMN2. Compounds which increase the expression of SMN2 could, therefore, be potential therapeutics for SMA. Ultrahigh-throughput screening recently identified substituted quinazolines as potent SMN2 inducers. A series of C5-quinazoline derivatives were tested for their ability to increase SMN expression in vivo. Oral administration of three compounds (D152344, D153249 and D156844) to neonatal mice resulted in a dose-dependent increase in Smn promoter activity in the central nervous system. We then examined the effect of these compounds on the progression of disease in SMN lacking exon 7 (SMNDelta7) SMA mice. Oral administration of D156844 significantly increased the mean lifespan of SMNDelta7 SMA mice by approximately 21-30% when given prior to motor neuron loss. In summary, the C5-quinazoline derivative D156844 increases SMN expression in neonatal mouse neural tissues, delays motor neuron loss at PND11 and ameliorates the motor phenotype of SMNDelta7 SMA mice.

Hyaluronidases are enzymes that mediate the breakdown of hyaluronan (HA), a large polysaccharide abundant in the extracellular matrix of vertebrate tissues. Six genes have been predicted to encode hyaluronidases in humans, but the protein products of only SPAM1, HYAL1, and HYAL2 have been characterized. We have now expressed the mouse Hyal3 gene product, hyaluronidase 3 (Hyal3), in Baby Hamster Kidney (BHK) cells and demonstrated the presence of multiple forms of Hyal3 ranging from approximately 45 to 56 kDa in expression lysates. Complete and partial digestions of the expressed protein with PNGase F showed three N-linked oligosaccharides accounted for all forms of Hyal3 detected in expression lysates. Most of these oligosaccharides were Endo H sensitive, indicating that they were high mannose or hybrid N-linked oligosaccharides. Subcellular fractionation of Hyal3-expressing BHK cells by density gradient centrifugation revealed most Hyal3 in a low-density vesicular population. Low levels of Hyal3 were detected in higher density vesicles, but no colocalization with the late endosomal/lysosomal marker Lamp1 was found by immunofluorescence microscopy. BHK cells stably expressing Hyal3 had increased acid-active hyaluronidase activity, but no such activity was detected when Hyal3 was transfected into Hyaluronidase 1 (Hyal1)-deficient fibroblasts. Overexpression of Hyal3 in BHK cells increased the Hyal1 protein and mRNA levels, suggesting that the increased hyaluronidase activity in these cells was due to Hyal1 rather than Hyal3. The results indicate that Hyal3 overexpressed in cultured cells lacks intrinsic hyaluronidase activity and that Hyal3 may contribute to HA metabolism by augmenting the activity of Hyal1.

A deficiency of 3-phosphoglycerate dehydrogenase (PHGDH) is a disorder of serine biosynthesis identified in children with congenital microcephaly, seizures, and severe psychomotor retardation. We report here the identification of the 1468G-->A (V490M) mutation of this gene in two siblings of an Ashkenazi Jewish family, providing further evidence that the V490M mutation is a common, panethnic cause of this deficiency. Using a novel, DNA-based diagnostic test, the mutation was not detected in 400 non-Jewish controls; one heterozygote was found among 400 persons of Ashkenazi Jewish ethnicity. Extensive biochemical studies were undertaken to characterize the effect of this mutation on enzyme activity, turnover, and stability. The V490M PHGDH yielded less than 35% of the activity observed for the wild-type enzyme when overexpressed by transient transfection or when comparing the endogenous activity in fibroblast cells from the patients with controls. Immunoblotting studies showed a comparable reduction in the level of immunoreactive PHGDH in cells expressing the mutant enzyme. Pulse-chase experiments with metabolically labeled PHGDH indicated that this resulted from an increased rate of degradation of the mutant enzyme following its synthesis. Thermolability analyses of mutant and wild-type enzyme activity revealed no significant differences. While others have proposed that the V490M mutation decreases the V(max) of the enzyme, we conclude that this mutation impairs the folding and/or assembly of PHGDH but has minimal effects on the activity or stability of that portion of the V490M mutant that reaches a mature conformation.

Protein kinase CK2, which was formerly known as casein kinase II, is a highly conserved protein serine/threonine kinase implicated in the control of cell proliferation through its phosphorylation of regulatory nuclear proteins. The enzyme consists of catalytic (alpha and (or) alpha') subunits and beta subunits that modulate the activity of the catalytic subunits. These subunits are arranged in homotetrameric (i.e., alpha 2 beta 2 or alpha' 2 beta 2) or heterotetrameric (i.e., alpha alpha' beta 2) complexes. We previously demonstrated using the yeast two-hybrid system that alpha (or alpha') subunits can interact with beta subunits but not other alpha (or alpha') subunits. By comparison, beta subunits can interact with alpha (or alpha') and with beta subunits, suggesting that the protein kinase CK2 holoenzyme forms because of the ability of beta subunits to dimerize, bringing two heterodimers (alpha beta or alpha' beta) into a tetrameric complex. In the present study, we used the yeast two-hybrid system to examine the domains of interactions between the alpha and beta subunits of protein kinase CK2. These studies indicate that the ability of beta to interact with alpha resides within the carboxy-terminal domain of beta. By comparison, our studies suggest that individual domains of alpha are not sufficient for interactions with beta.

The alpha and beta subunits of casein kinase II are dramatically phosphorylated in cells that are arrested in mitosis (Litchfield, D. W., Lüscher, B., Lozeman, F. J., Eisenman, R. N., and Krebs, E.G. (1992) J. Biol. Chem. 267, 13943-13951). Comparative phosphopeptide mapping experiments indicated that the mitotic phosphorylation sites on the alpha subunit of casein kinase II can be phosphorylated in vitro by p34cdc2. In the present study, we have demonstrated that a glutathione S-transferase fusion protein encoding the C-terminal 126 amino acids of the alpha subunit is phosphorylated by p34cdc2 at the same sites as intact casein kinase II, indicating that the mitotic phosphorylation sites are localized within the C-terminal domain of alpha. Four residues within this domain, Thr-344, Thr-360, Ser-362, and Ser-370, conform to the minimal consensus sequence for p34cdc2 phosphorylation. Synthetic peptides corresponding to regions of alpha that contain each of these residues are phosphorylated by p34cdc2 at these sites. Furthermore, alterations in the phosphorylation of the glutathione S-transferase proteins encoding the C-terminal domain of alpha are observed when any of the four residues are mutated to alanine. When all four residues are mutated to alanine, the fusion protein is no longer phosphorylated by p34cdc2 at any of the sites that are phosphorylated in mitotic cells. These results indicate that Thr-344, Thr-360, Ser-362, and Ser-370 are the sites on the alpha subunit of casein kinase II that are phosphorylated in mitotic cells.

Casein kinase II is a highly conserved enzyme that is essential for viability. In cells, the casein kinase II beta-subunit is phosphorylated at an autophosphorylation site and at a site (Ser-209) that is maximally phosphorylated in mitotic cells. To identify protein kinase activities that phosphorylate Ser-209, we fractionated extracts from mitosis-arrested human Burkitt lymphoma MANCA cells. A single Ser-209 kinase activity was detected following each fractionation step. The Ser-209 kinase was purified to a specific activity of approx. 250 nmol/min per mg and efficiently phosphorylated histone H1, a synthetic peptide containing Ser-209 (Ser-209 peptide), myelin basic protein and casein. Immunoblot analysis demonstrated that all fractions containing Ser-209 kinase activity contained p34cdc2. Furthermore, depletion of the Ser-209 kinase activity with p13suc1-Sepharose and anti-p34cdc2 antiserum demonstrated conclusively that the isolated Ser-209 kinase is p34cdc2. These studies provide strong biochemical evidence that p34cdc2 is the enzyme that phosphorylates Ser-209 on the beta-subunit of CKII in mitotic cells. In addition, these results indicate that the Ser-209 peptide can be utilized as a specific reagent for the assay of p34cdc2 activity in mitotic extracts, since no other Ser-209 peptide kinase activities were detected.