The cellular response to ocean warming in .

Marine phytoplankton contribute substantially to the global flux of carbon from the atmosphere to the deep ocean. Sea surface temperatures will inevitably increase in line with global climate change, altering the performance of marine phytoplankton. Differing sensitivities of photosynthesis and respiration to temperature, will likely shift the strength of the future oceanic carbon sink.

Cerebrospinal Fluid and Brain Proteoforms of the Granin Neuropeptide Family in Alzheimer's Disease.

The granin neuropeptide family is composed of acidic secretory signaling molecules that act throughout the nervous system to help modulate synaptic signaling and neural activity. Granin neuropeptides have been shown to be dysregulated in different forms of dementia, including Alzheimer's disease (AD). Recent studies have suggested that the granin neuropeptides and their protease-cleaved bioactive peptides (proteoforms) may act as both powerful drivers of gene expression and as a biomarker of synaptic health in AD.

The Role of in Campylobacter jejuni Beyond Intercellular Signaling.

The full role of the gene in the biological processes, such as essential amino acid synthesis, nitrogen and pyruvate metabolism, and flagellar assembly, of Campylobacter jejuni has not been clearly described to date. Therefore, in this study, we used a comprehensive approach at the cellular and molecular levels, including transcriptomics and proteomics, to investigate the key role of the gene and compared C. jejuni 11168Δ ( mutant) and C.

Ubiquitin-based pathway acts inside chloroplasts to regulate photosynthesis.

Photosynthesis is the energetic basis for most life on Earth, and in plants it operates inside double membrane-bound organelles called chloroplasts. The photosynthetic apparatus comprises numerous proteins encoded by the nuclear and organellar genomes. Maintenance of this apparatus requires the action of internal chloroplast proteases, but a role for the nucleocytosolic ubiquitin-proteasome system (UPS) was not expected, owing to the barrier presented by the double-membrane envelope.

CDK9 and PP2A regulate RNA polymerase II transcription termination and coupled RNA maturation.

CDK9 is a kinase critical for the productive transcription of protein-coding genes by RNA polymerase II (pol II). As part of P-TEFb, CDK9 phosphorylates the carboxyl-terminal domain (CTD) of pol II and elongation factors, which allows pol II to elongate past the early elongation checkpoint (EEC) encountered soon after initiation. We show that, in addition to halting pol II at the EEC, loss of CDK9 activity causes premature termination of transcription across the last exon, loss of polyadenylation factors from chromatin, and loss of polyadenylation of nascent transcripts.

CAPTURE of the Human U2 snRNA Genes Expands the Repertoire of Associated Factors.

In order to identify factors involved in transcription of human snRNA genes and 3' end processing of the transcripts, we have carried out CRISPR affinity purification in situ of regulatory elements (CAPTURE), which is deadCas9-mediated pull-down, of the tandemly repeated U2 snRNA genes in human cells. CAPTURE enriched many factors expected to be associated with these human snRNA genes including RNA polymerase II (pol II), Cyclin-Dependent Kinase 7 (CDK7), Negative Elongation Factor (NELF), Suppressor of Ty 5 (SPT5), Mediator 23 (MED23) and several subunits of the Integrator Complex. Suppressor of Ty 6 (SPT6); Cyclin K, the partner of Cyclin-Dependent Kinase 12 (CDK12) and Cyclin-Dependent Kinase 13 (CDK13); and SWI/SNF chromatin remodelling complex-associated SWI/SNF-related, Matrix-associated, Regulator of Chromatin (SMRC) factors were also enriched.

Alkaline nucleoplasm facilitates contractile gene expression in the mammalian heart.

Cardiac contractile strength is recognised as being highly pH-sensitive, but less is known about the influence of pH on cardiac gene expression, which may become relevant in response to changes in myocardial metabolism or vascularization during development or disease. We sought evidence for pH-responsive cardiac genes, and a physiological context for this form of transcriptional regulation. pHLIP, a peptide-based reporter of acidity, revealed a non-uniform pH landscape in early-postnatal myocardium, dissipating in later life.

The C-Terminal Domains of the PB2 Subunit of the Influenza A Virus RNA Polymerase Directly Interact with Cellular GTPase Rab11a.

Influenza A virus (IAV) contains a segmented RNA genome that is transcribed and replicated by the viral RNA polymerase in the cell nucleus. Replicated RNA segments are assembled with viral polymerase and oligomeric nucleoprotein into viral ribonucleoprotein (vRNP) complexes which are exported from the nucleus and transported across the cytoplasm to be packaged into progeny virions. Host GTPase Rab11a associated with recycling endosomes is believed to contribute to this process by mediating the cytoplasmic transport of vRNPs.

Acyl carrier protein promotes MukBEF action in Escherichia coli chromosome organization-segregation.

Structural Maintenance of Chromosomes (SMC) complexes act ubiquitously to compact DNA linearly, thereby facilitating chromosome organization-segregation. SMC proteins have a conserved architecture, with a dimerization hinge and an ATPase head domain separated by a long antiparallel intramolecular coiled-coil. Dimeric SMC proteins interact with essential accessory proteins, kleisins that bridge the two subunits of an SMC dimer, and HAWK/KITE proteins that interact with kleisins.

Cardiomyocyte Na/H Exchanger-1 Activity Is Reduced in Hypoxia.

Fully-activated Na/H exchanger-1 (NHE1) generates the cardiomyocyte's largest trans-membrane extrusion of H ions for an equimolar influx of Na ions. This has the desirable effect of clearing excess intracellular acidity, but comes at a large energetic premium because the exchanged Na ions must ultimately be extruded by the sodium pump, a process that consumes the majority of the heart's non-contractile ATP. We hypothesize that the state of NHE1 activation depends on metabolic resources, which become limiting in periods of myocardial hypoxia.

The WHHERE coactivator complex is required for retinoic acid-dependent regulation of embryonic symmetry.

Bilateral symmetry is a striking feature of the vertebrate body plan organization. Vertebral precursors, called somites, provide one of the best illustrations of embryonic symmetry. Maintenance of somitogenesis symmetry requires retinoic acid (RA) and its coactivator Rere/Atrophin2.

The TAF10-containing TFIID and SAGA transcriptional complexes are dispensable for early somitogenesis in the mouse embryo.

During development, tightly regulated gene expression programs control cell fate and patterning. A key regulatory step in eukaryotic transcription is the assembly of the pre-initiation complex (PIC) at promoters. PIC assembly has mainly been studied , and little is known about its composition during development.

MRG15-mediated tethering of PALB2 to unperturbed chromatin protects active genes from genotoxic stress.

The partner and localiser of BRCA2 (PALB2) plays important roles in the maintenance of genome integrity and protection against cancer. Although PALB2 is commonly described as a repair factor recruited to sites of DNA breaks, recent studies provide evidence that PALB2 also associates with unperturbed chromatin. Here, we investigated the previously poorly described role of chromatin-associated PALB2 in undamaged cells.

ISCA1 is essential for mitochondrial FeS biogenesis in vivo.

Mammalian A-type proteins, ISCA1 and ISCA2, are evolutionarily conserved proteins involved in iron-sulfur cluster (Fe-S) biogenesis. Recently, it was shown that ISCA1 and ISCA2 form a heterocomplex that is implicated in the maturation of mitochondrial FeS proteins. Here we report that mouse ISCA1 and ISCA2 are FeS-containing proteins that combine all features of Fe-S carrier proteins.

KAT2-mediated PLK4 acetylation contributes to genomic stability by preserving centrosome number.

We have recently identified the first human lysine (K) acetyltransferase 2A and 2B (called KAT2A/2B; known also as GCN5/PCAF, respectively)-dependent acetylome and revealed a mechanism by which KAT2A/2B-mediated acetylation of serine/threonine polo-like kinase 4 (PLK4) maintains correct centrosome number in human cells, therefore contributing to the maintenance of genome stability..

KAT2A/KAT2B-targeted acetylome reveals a role for PLK4 acetylation in preventing centrosome amplification.

Lysine acetylation is a widespread post-translational modification regulating various biological processes. To characterize cellular functions of the human lysine acetyltransferases KAT2A (GCN5) and KAT2B (PCAF), we determined their acetylome by shotgun proteomics. One of the newly identified KAT2A/2B substrate is polo-like kinase 4 (PLK4), a key regulator of centrosome duplication.

Cytoplasmic TAF2-TAF8-TAF10 complex provides evidence for nuclear holo-TFIID assembly from preformed submodules.

General transcription factor TFIID is a cornerstone of RNA polymerase II transcription initiation in eukaryotic cells. How human TFIID-a megadalton-sized multiprotein complex composed of the TATA-binding protein (TBP) and 13 TBP-associated factors (TAFs)-assembles into a functional transcription factor is poorly understood. Here we describe a heterotrimeric TFIID subcomplex consisting of the TAF2, TAF8 and TAF10 proteins, which assembles in the cytoplasm.

Mapping the deubiquitination module within the SAGA complex.

The molecular organization of the yeast transcriptional coactivator Spt-Ada-Gcn5 acetyltransferase (SAGA) was analyzed by single-particle electron microscopy. Complete or partial deletion of the Sgf73 subunit disconnects the deubiquitination (DUB) module from SAGA and favors in our conditions the cleavage of the C-terminal ends of the Spt7 subunit and the loss of the Spt8 subunit. The structural comparison of the wild-type SAGA with two deletion mutants positioned the DUB module and enabled the fitting of the available atomic models.

Mof-associated complexes have overlapping and unique roles in regulating pluripotency in embryonic stem cells and during differentiation.

The histone acetyltransferase (HAT) Mof is essential for mouse embryonic stem cell (mESC) pluripotency and early development. Mof is the enzymatic subunit of two different HAT complexes, MSL and NSL. The individual contribution of MSL and NSL to transcription regulation in mESCs is not well understood.

The cohesin complex regulates immunoglobulin class switch recombination.

Immunoglobulin (Ig) class switch recombination (CSR) is initiated by the transcription-coupled recruitment of activation-induced cytidine deaminase (AID) to switch regions and by the subsequent generation of double-stranded DNA breaks (DSBs). These DNA breaks are ultimately resolved through the nonhomologous end joining (NHEJ) pathway. We show that during CSR, AID associates with subunits of cohesin, a complex previously implicated in sister chromatid cohesion, DNA repair, and the formation of DNA loops between enhancers and promoters.

The human TREX-2 complex is stably associated with the nuclear pore basket.

In eukaryotes, mRNA export involves many evolutionarily conserved factors that carry the nascent transcript to the nuclear pore complex (NPC). The THO/TREX complex couples transcription to mRNA export and recruits the mRNA export receptor NXF1 for the transport of messenger ribonucleoprotein particles (mRNP) to the NPC. The transcription and export complex 2 (TREX-2) was suggested to interact with NXF1 and to shuttle between transcription sites and the NPC.

The ATAC acetyl transferase complex controls mitotic progression by targeting non-histone substrates.

All DNA-related processes rely on the degree of chromatin compaction. The highest level of chromatin condensation accompanies transition to mitosis, central for cell cycle progression. Covalent modifications of histones, mainly deacetylation, have been implicated in this transition, which also involves transcriptional repression.