The advent of Big Data science (BDs) has generated enormous amounts, varieties, and sources of complex datasets that have vast potential for the creation of new knowledge, particularly in relation to primary and secondary disease prevention (Eaton et al., 2012); yet BDs also brings inherent challenges of utilization and value.A critical cross-cutting issue is the creation of a compelling and effective user experience that can empower biomedical researchers and trainees with limited information technology budgets access to powerful and intuitive tools designed to effectively address the challenges posed by the four dimensions of Big Data: (1) volume: the vast amount of data that is generated through source integration; (2) variety: the lack of standardization that is inherent in combining data from different resources; (3) velocity: the high rate at which data is constantly changing; and (4) veracity: the need for reliability measures and safeguards protecting the confidentiality of the individuals involved (Otero, Hersh, & Jai Ganesh, 2014).These challenges are particularly pronounced in neuroscience Big Data, as neuroimaging produces some of the largest and most complex data types (Van Horn & Toga, 2014;Turner & Van Horn, 2012;Bowman, Joshi, & Van Horn, 2012).Through advances in neuroimaging techniques, such as functional magnetic resonance image (fMRI) and positron emission tomography (PET), massive stores of highresolution and high-dimensional brain images
Our recent work showed that TMEM163 is a zinc efflux transporter that belongs to the cation diffusion facilitator (CDF) family of proteins. We propose that the TMEM163 be now called ZNT11 as a new member of the Group 1 CDF family ZNT efflux proteins that include 10 mammalian zinc transporters, ZNT1‐ZNT10. Accordingly, we hypothesize that TMEM163/ZNT11 interacts with at least one of the ZNT proteins, namely ZNT1 and ZNT2, based on its structural and functional characteristics. To show that TMEM163/ZNT11 interacts with either ZNT1 or ZNT2, we cloned their cDNAs into mammalian expression constructs containing either Myc‐DDK or HA peptide tag. Using HEK‐293 cells, we individually transfected TMEM163/ZNT11, ZNT1, and ZNT2 constructs as negative controls, while we co‐transfected TMEM163/ZNT11 and ZNT1, or TMEM163/ZNT11 and ZNT2. As a positive control, we co‐transfected HA‐tagged TMEM163/ZNT11 with a Myc‐DDK‐tagged TMEM163/ZNT11 construct in HEK‐293 cells, based on a previous report that its rodent counterpart exists as a homodimer. We then used a co‐immunoprecipitation assay using either anti‐HA‐ or anti‐DDK‐bound agarose beads to pull down one of the target proteins. Western blot analysis showed that TMEM163/ZNT11 physically bound ZNT1 or ZNT2 protein. To determine the functional relevance of the interaction, we performed zinc flux assays using two zinc‐specific fluorescence dyes, Fluozin‐3 (high affinity, membrane impermeable) and Newport Green (low affinity, membrane permeable) following single‐ and co‐transfection of TMEM163/ZNT11, ZNT1, and ZNT2 constructs in HeLa cells. Our results confirmed that homodimers of TMEM163/ZNT11, ZNT1, and ZNT2 proteins transport zinc out of the cells, but that the efflux activity of homodimer TMEM163/ZNT11 proteins varied slightly in magnitude when compared with heterodimers of TMEM163/ZNT11 and ZNT1, or TMEM163/ZNT11 and ZNT2 proteins. These results suggest that the interaction between TMEM163/ZNT11 and distinct ZNT proteins is physiologically relevant and may serve to modify the transport activity of ZNT protein interactor. Overall, our investigations showed for the first time that TMEM163/ZNT11 forms functional heterodimers with ZNT1 and ZNT2 proteins. Thus, TMEM163/ZNT11 by itself, or in combination with one of these specific ZNT proteins, may play a crucial role in maintaining intracellular zinc homeostasis in specific cell types. Support or Funding Information This work is funded by NIH R15 NS101594.
It has been nearly 15 years since the suggestion that synaptically released Zn2+ might contribute to excitotoxic brain injury after seizures, stroke, and brain trauma. In the original “zinc-translocation” model, it was proposed that synaptically released Zn2+ ions penetrated postsynaptic neurons, causing injury. According to the model, chelating zinc in the cleft was predicted to be neuroprotective. This proved to be true: zinc chelators have proved to be remarkably potent at reducing excitotoxic neuronal injury in many paradigms. Promising new zinc-based therapies for stroke, head trauma, and epileptic brain injury are under development. However, new evidence suggests that the original translocation model was incomplete. As many as three sources of toxic zinc ions may contribute to excitotoxicity: presynaptic vesicles, postsynaptic zincsequestering proteins, and (more speculatively) mitochondrial pools. The authors present a new model of zinc currents and zinc toxicity that offers expanded opportunities for zinc-selective therapeutic chelation interventions.
The master regulator CtrA oscillates during the Caulobacter cell cycle due to temporally regulated proteolysis and transcription. It is proteolysed during the G1-S transition and reaccumulates in predivisional cells as a result of transcription from two sequentially activated promoters, P1 and P2. CtrA reinforces its own synthesis by directly mediating the activation of P2 concurrently with repression of P1. To explore the role of P1 in cell cycle control, we engineered a mutation into the native ctrA locus that prevents transcription from P1 but not P2. As expected, the ctrA P1 mutant exhibits striking growth, morphological and DNA replication defects. Unexpectedly, we found CtrA and its antagonist SciP, but not DnaA, GcrA or CcrM accumulation to be dramatically reduced in the ctrA P1 mutant. SciP levels closely paralleled CtrA accumulation, suggesting that CtrA acts as a rheostat to modulate SciP abundance. Furthermore, the reappearance of CtrA and CcrM in predivisional cells was delayed in the P1 mutant by 0.125 cell cycle unit in synchronized cultures. High levels of ccrM transcription despite low levels of CtrA and increased transcription of ctrA P2 in the ctrA P1 mutant are two examples of robustness in the cell cycle. Thus, Caulobacter can adjust regulatory pathways to partially compensate for reduced and delayed CtrA accumulation in the ctrA P1 mutant.
The loss of function in the Transient Receptor Potential Mucolipin‐1 (TRPML1) protein, encoded by the Mucolipin‐1 ( MCOLN1 ) gene, is known to cause the neurodegenerative disease Mucolipidosis type IV (MLIV). Characteristics of MLIV are motor problems, cognitive dysfunction, achlorhydria, cataracts, and blindness caused by retinal cell death. The Ashkenazi Jew population is most afflicted by the disease, and MLIV has no known cure. The Mucolipin ion channels consist of TRPML1, ‐2, and ‐3 proteins, which are encoded by MCOLN1 , ‐2 , and ‐3 genes, respectively. They are known to serve as non‐selective cation channels located within endosomes and lysosomes and play a role in endosome‐lysosome fusion. Previous research indicates that TRPML1 and TRPML2 proteins share a high degree of homology, and we hypothesize that TRPML 2 , which has no known association to clinical disease, could substitute for the loss of functional TRPML1 in MLIV, resulting in a rescue of the disease phenotype. In order to study the potential therapeutic effects of TRPML2 in MLIV, we must first show that it is expressed in the brain, one of the tissues most affected by MLIV. We have previously discovered PAX5 as the transcriptional activator for MCOLN2 and have shown that MCOLN2 expression could be heterologously induced in both human neuroglioma (H4) cells and human embryonic kidney 293 (HEK‐293) cell lines. Previous reports demonstrated that MCOLN2 has tissue‐specific expression with little to no detectable transcripts in brain tissue. However, our preliminary research has detected endogenous levels of MCOLN2 transcripts in human H4 and neuroblastoma (SH‐SY5Y) cells. Moreover, to induce the expression of endogenous MCOLN2, we transduced SH‐SY5Y cells with adenovirus and lentivirus vectors containing the PAX5 cDNA. PAX5 serves as a B cell‐specific activator protein with tissue‐specific expression pattern as well. Standard reverse‐transcription polymerase chain reaction (RT‐PCR) and real‐time quantitative RT‐PCR both revealed MCOLN2 expression in SH‐SY5Y cells at 48 and 72 hours post‐transduction. We show that PAX5 transcriptionally activates and increases endogenous MCOLN2 expression in neuronal cells that are central to studying MLIV. Future studies include In‐Cell Western assay with an anti‐TRPML2 antibody and transcriptome analysis of PAX5‐treated cells to determine global gene expression. These results and future studies will further explore the therapeutic potential of gene complementation to rescue the cellular phenotype in MLIV disease. Support or Funding Information This work was partly funded by NIH R15 NS101594. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .
