HnRNP Q Has a Suppressive Role in the Translation of Mouse Cryptochrome1

Precise regulation of gene expression is especially important for circadian timekeeping which is maintained by the proper oscillation of the mRNA and protein of clock genes and clock-controlled genes. As a main component of the core negative arm feedback loops in the circadian clock, the Cry1 gene contributes to the maintenance of behavioral and molecular rhythmicity. Despite the central role of Cry1, the molecular mechanisms regulating expression levels of Cry1 mRNA and protein are not well defined. In particular, the post-transcriptional regulation of Cry1 mRNA fate decisions is unclear. Here, we demonstrate that hnRNP Q binds to mCry1 mRNA via the 5'UTR. Furthermore, hnRNP Q inhibits the translation of mCry1 mRNA, leading to altered rhythmicity in the mCRY1 protein profile.1145Ysciescopu

A two-photon fluorescent probe for lysosomal zinc ions

The selective detection of zinc ions in lysosomes over that in cytosol is achieved with a fluorescent probe, which enabled the fluorescence imaging of endogenous zinc ions in lysosomes of NIH 3T3 cells as well as mouse hippocampal tissues by two-photon microscopy under excitation at 900 nm.open

Leisure time physical activity: a protective factor against metabolic syndrome development

Abstract Purpose Physical activity (PA) is a modifiable factor in preventing/treating cardiometabolic disease. However, no studies have yet compared specific moderate-to-vigorous PA (MVPA) domains with the risk of metabolic syndrome (MetS) in detail. Here, the present study was conducted to examine the impact of different MVPA domains (leisure-time PA (LTPA) vs. occupational PA (OPA) vs. total MVPA) on the risk of MetS in Korean adults. Materials and methods: Data from the 2014 to 2021 Korea National Health and Nutrition Examination Survey were analyzed (N = 31,558). MetS was defined according to the criteria by revised NCEP/ATP-III. The domain-specific MVPA was assessed using the K-GPAQ. The LTPA and OPA status were classified into four categories: (1) 0 min/week, (2) 1 to 149 min/week, (3) 150 to 299 min/week, and 4) ≥ 300 min/week. In addition, the present study calculated total MVPA as a sum of OPA and LTPA and further classified it into six groups; (1) 0 min/week, (2) 1 to 149 min/week, (3) 150 to 299 min/week, (4) 300 to 449 min/week, (5) 450 to 599 min/week, 6) ≥ 600 min/week. Results: The ≥ 300 min/week and the 150 to 299 min/week of LTPA showed better outcomes in cardiometabolic disease risk factors and surrogate markers of insulin resistance compared with the 0 min/week of LTPA regardless of adiposity status. Risk of MetS in ≥ 300 min/week of LTPA was lower than in 0 min/week, 1 to 149 min/week, and 150 to 299. In addition, LTPA was significantly associated with a risk of the MetS in a curvilinear dose-response curve, however, no significant effects of a non-linear relationship between OPA and risk of the MetS. Conclusions: Our findings showed that LTPA was associated with a risk of MetS with a dose-response curve, whereas no significant non-linear effects were found between OPA and the risk of MetS. Therefore, the MVPA domain is an independent factor of the risk of MetS

HnRNP Q Has a Suppressive Role in the Translation of Mouse Cryptochrome1

<div><p>Precise regulation of gene expression is especially important for circadian timekeeping which is maintained by the proper oscillation of the mRNA and protein of clock genes and clock-controlled genes. As a main component of the core negative arm feedback loops in the circadian clock, the Cry1 gene contributes to the maintenance of behavioral and molecular rhythmicity. Despite the central role of Cry1, the molecular mechanisms regulating expression levels of Cry1 mRNA and protein are not well defined. In particular, the post-transcriptional regulation of Cry1 mRNA fate decisions is unclear. Here, we demonstrate that hnRNP Q binds to mCry1 mRNA via the 5′UTR. Furthermore, hnRNP Q inhibits the translation of mCry1 mRNA, leading to altered rhythmicity in the mCRY1 protein profile.</p></div

ACTIVITY-DEPENDENT LOCAL TRANSLATION OF GLUA1 IS REGULATED BY HNRNP A2/B1

AMPA receptor subunit GluA1 is essential for induction of synaptic plasticity. Mounting evidence demonstrates the regulations of AMPA receptor expression, but underlying molecular mechanisms of the GluA1 protein synthesis elicited by synaptic activity are not fully understood. Here, we show that brain-derived neurotrophic factor (BDNF) stimulation results in the increase of GluA1 local translation. We also demonstrate that heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 interacts with GluA1 mRNA and mediates internal translational initiation of GluA1 in hippocampal neuronal dendrites. Moreover, we directly visualize newly synthesized GluA1 in neuronal compartments. Furthermore, the BDNF-induced GluA1 local translation as well as GluA1 total and surface expressions are significantly inhibited in the hnRNP A2/B1 deficient neuron. Taken together, hnRNP A2/B1-mediated translational regulation of GluA1 mRNA provides novel aspect for activity- dependent local expression of AMPA receptor.2

hnRNP Q binds to the 5′UTR of mCry1 and suppresses its translation.

<p>(A) RNAi screening in NIH3T3 cells. Five different siRNAs targeting different hnRNPs, including hnRNP Q, were transfected into cells. Control siRNA was used as a negative control. The level of mCRY1 protein was analyzed by Western blotting. On the right side, the circadian phases of cell populations were synchronized by temporal treatment with 100nM dexamethasone, to clearly check the collective effect of hnRNP downregulation on each cell. At 12 hours after synchronization, samples were analyzed. GAPDH and 14-3-3ζ were used as a loading control. The arrow indicates weakly detected mCRY1 protein. (B) mRNA stability of endogenous mCry1 under hnRNP Q downregulation. mRNA degradation kinetics of mTBP was also evaluated as a control. Error bars represent the SEM of three independent experiments. *P<0.05. (C) Identification of the interaction between the mCry1 5′UTR and hnRNP Q by RNA affinity purification followed by immunoblotting. (D) The translation enhancement mediated by the 5′UTR of mCry1 after reduction of hnRNP Q is shown. The 5′UTR of mCry1 was inserted at the upstream of the Fluc coding sequence. Fluc activity was normalized with β-Gal activity. Error bars represent the SEM of seven independent experiments. *P<0.05. (E) Knockdown of hnRNP Q was confirmed by immunoblotting.</p

RNA-binding protein HNRNP A1 promotes lung cancer cell proliferation by targeting VRK1

RNA-binding proteins (RBPs) are key players in post- transcriptional events. Dysregulation of gene expression is associated with a variety of diseases, including lung cancer. Vaccinia-related kinase 1 (VRK1) is a master regulator in lung adenocarcinoma and is considered a key molecule in the adaptive pathway, which mainly controls cell proliferation and survival. Previous studies have shown that VRK1 was significantly increased in various cancer cells, but detailed understanding for gene regulatory mechanisms of VRK1 is still unknown. Here we demonstrate that heterogeneous nuclear ribonucleoprotein (hnRNP) A1 enhances VRK1 mRNA translation. We found that 3′UTR of VRK1 mRNA increased protein amounts and hnRNP A1 binds to the 3′UTR of VRK1 mRNA. Furthermore, hnRNP A1 interacted with eukaryotic translation initiation factors and also directly associated with ribosomal proteins, resulting in translation of VRK1 mRNA in a 3′UTR-dependent manner. In conclusion, overexpression of hnRNP A1 promotes cell proliferation and invasion in lung cancer by regulating the level of VRK1 and have potential as therapeutic targets.2

DAP5 promotes axonal outgrowth by increasing the translation of DSCR1.4

Spatial and temporal regulation of protein synthesis in axon is important for axon outgrowth and steering. Down syndrome candidate region 1(DSCR1) regulates actin filaments formation and local translation in axon by controling calcineurin, phospatase. However, it is unknown whether DSCR1 mRNA is locally translated in axon. Here, we investigated that DSCR1.4 mRNA, one of DSCR1 isoform exist and is translated in both soma and axon. Not only cap-dependent but also cap-independent translation is important for DSCR1.4 protein synthesis. Translation of DSCR1.4 mRNA is increased by Death-associated protein 5 (DAP5). DSCR1.4 increased by DAP5 makes axons longer. These findings have implications for understanding relation of local translation and axon outgrowth, steering.2

hnRNP D, hnRNP Q and PTB regulates Cap-independent translation of Profilin1

Profilin1 is a ubiquitously expressed regulator of actin dynamics. Profilin1 has diverse and critical roles in cell migration, proliferation, signaling and cell survival through actin cytoskeletal regulation. Moreover, profilin1 is also important for axonal outgrowth and spinogenesis of neurons. Lack of profilin1 shortens axon length and inhibit spine formation. Thus, identifying the regulation mechanisms of profilin1 is essential. However, the regulation mechanisms of profilin1 remains still unknown. Here, we observed that profilin1 mRNA is translated by both cap-dependent and cap-independent initiation mechanisms. The cap-independent translation of profilin1 is regulated by hnRNP Q, hnRNP D and PTB. We confirmed that they binds to the 5’UTR of profilin1 mRNA. Knock-down of hnRNP Q and hnRNP D increased profilin1 mRNA translation. PTB knock-down inhibit the cap-independent translation of profilin1. Thus, our findings suggest that hnRNP Q and hnRNP D function as negative regulators and PTB functions as a positive regulator. Our findings suggest a new translational regulatory mechanism for profilin1 expressions.2

mCry1 protein oscillation is less evident under hnRNP Q silencing.

<p>(A) qRT-PCR analysis for endogenous mCry1 mRNA levels after circadian phase synchronization. Error bars represent the SEM of five independent experiments. The initial amount of mCry1 mRNA with siCon was arbitrarily set as 1. *P<0.05. (B) Western blot analysis of mCRY1 in control and hnRNP Q-downregulated cells. (C) The normalized relative expression profile of mCRY1 protein in (B) was plotted. The intensities at 0 hour of siCon group were arbitrarily set as 1. (D) Downregulation of hnRNP Q was confirmed by immunoblotting.</p