Fine-tuning p53 activity by modulating the interaction between eukaryotic translation initiation factor eIF4E and RNA-binding protein RBM38.

p53 is critical for tumor suppression but also elicits detrimental effects when aberrantly overexpressed. Thus, multiple regulators, including RNA-binding protein RBM38, are found to tightly control p53 expression. Interestingly, RBM38 is unique in that it can either suppress or enhance p53 mRNA translation via altered interaction with eIF4E potentially mediated by serine-195 (S195) in RBM38. Thus, multiple RBM38/eIF4E knock-in (KI) cell lines were generated to investigate the significance of eIF4E-RBM38 interaction in controlling p53 activity. We showed that KI of RBM38-S195D or -Y192C enhances, whereas KI of RBM38-S195K/R/L weakens, the binding of eIF4E to p53 mRNA and subsequently p53 expression. We also showed that KI of eIF4E-D202K weakens the interaction of eIF4E with RBM38 and thereby enhances p53 expression, suggesting that D202 in eIF4E interacts with S195 in RBM38. Moreover, we generated an Rbm38 S193D KI mouse model in which human-equivalent serine-193 is substituted with aspartic acid. We showed that S193D KI enhances p53-dependent cellular senescence and that S193D KI mice have a shortened life span and are prone to spontaneous tumors, chronic inflammation, and liver steatosis. Together, we provide in vivo evidence that the RBM38-eIF4E loop can be explored to fine-tune p53 expression for therapeutic development.

Genome-wide association study of stem structural characteristics that extracted by a high-throughput phenotypic analysis "LabelmeP rice" in rice.

Stem is important for assimilating transport and plant strength; however, less is known about the genetic basis of its structural characteristics. In this study, a high-throughput method, "LabelmeP rice" was developed to generate 14 traits related to stem regions and vascular bundles, which allows the establishment of a stem cross-section phenotype dataset containing anatomical information of 1738 images from hand-cut transections of stems collected from 387 rice germplasm accessions grown over two successive seasons. Then, the phenotypic diversity of the rice accessions was evaluated. Genome-wide association studies identified 94, 83, and 66 significant single nucleotide polymorphisms (SNPs) for the assayed traits in 2 years and their best linear unbiased estimates, respectively. These SNPs can be integrated into 29 quantitative trait loci (QTL), and 11 of them were common in 2 years, while correlated traits shared 19. In addition, 173 candidate genes were identified, and six located at significant SNPs were repeatedly detected and annotated with a potential function in stem development. By using three introgression lines (chromosome segment substitution lines), four of the 29 QTLs were validated. LOC_Os01g70200, located on the QTL uq1.4, is detected for the area of small vascular bundles (SVB) and the rate of large vascular bundles number to SVB number. Besides, the CRISPR/Cas9 editing approach has elucidated the function of the candidate gene LOC_Os06g46340 in stem development. In conclusion, the results present a time- and cost-effective method that provides convenience for extracting rice stem anatomical traits and the candidate genes/QTL, which would help improve rice.

p73α1, a p73 C-terminal isoform, regulates tumor suppression and the inflammatory response via Notch1.

p73, a p53 family member, undergoes alternative splicing at the 3' end to produce multiple isoforms, but their expression and activity are largely unknown. Thus, CRISPR was used to knock out exon 12 (E12) in human cancer cell lines and mice, leading to isoform switch from p73α to isoform p73α1. We found that p73α1 is naturally expressed and induced by DNA damage. We also found that knockout of E12 suppresses cell growth and migration in H1299 and MIA PaCa-2 cells and promotes cellular senescence in mouse embryonic fibroblasts. Similarly, ectopic expression of p73α1 suppresses cell proliferation, whereas knockdown of p73α1 restores the cell proliferative and migratory capacities of E12−/− cells. Consistently, we found that E12+/− mice are not prone to spontaneous tumors. Instead, E12+/− mice are prone to systemic inflammation and exhibit elevated TNFα expression in inflamed tissues. Moreover, we found that Notch1, a master regulator of the inflammatory response, is regulated by p73α1 and highly expressed in E12−/− cells and inflamed E12+/− mouse tissues. Furthermore, through knockdown of p73α1 and/or Notch1 in E12−/− cells, we found that Notch1 is necessary for p73α1-mediated growth suppression. Together, these data suggest that p73α1 plays a critical role in tumor suppression and the inflammatory response via Notch1.

Tri-site Synergistic Cu(I)/Cu(II)─N Single-Atom Catalysts for Additive-Free CO2 Conversion.

As the highly stable and abundant carbon source in nature, the activation and conversion of CO2 into high-value chemicals is highly desirable yet challenging. The development of Cu(I)/Cu(II)─N tri-site synergistic single-atom catalysts (TS-SACs) with remarkable CO2 activation and conversion performance is presented, eliminating the need for external additives in cascade reactions. Under mild conditions (40 °C, atmospheric CO2), the catalyst achieves high yields (up to 99%) of valuable 2-oxazolidinones from CO2 and propargylamine. Notably, the catalyst demonstrates easy recovery, short reaction times, and excellent tolerance toward various functional groups. Supported by operando techniques and density functional theory calculations, it is elucidated that the spatially proximal Cu(I)/Cu(II)─N sites facilitate the coupling of multiple chemical transformations. This surpasses the performance of supported isolated Cu(I) or Cu(II) catalysts and traditional organic base-assisted cascade processes. These Cu(I)/Cu(II)─N tri-site synergistic atom active sites not only enable the co-activation of CO2 at the Cu(II)─N pair and alkyne at the Cu(I) site but also induce a di-metal locking geometric effect that accelerates the ring closure of cyclic carbamate intermediates. The work overcomes the limitations of single metal sites and paves the way for designing multisite catalysts for CO2 activation, especially for consecutive activation, tandem, or cascade reactions.

Simultaneously Engineering Oxygen Defects and Heterojunction into Ho-Doped ZnO Nanoflowers for Enhancing n-Propanol Gas Detection.

Lung cancer poses a serious threat to people's lives and health due to its high incidence rate and high mortality rate, making it necessary to effectively conduct early screening. As an important biomarker for lung cancer, the detection of n-propanol gas suffers from a low response value and a high detection limit. In this paper, flower-like Ho-doped ZnO was fabricated by the coprecipitation method for n-propanol detection at subppm concentrations. The gas sensor based on the 3% Ho-doped ZnO showed selectivity to n-propanol gas. Its response value to 100 ppm n-propanol was 341 at 140 °C, and its limit of detection (LOD) was about 25.6 ppb, which is lower than that of n-propanol in the breath of a healthy person (150 ppb). The calculation results show that the adsorption of n-propanol on a Ho-doped ZnO surface releases more energy than isopropanol, ethanol, formaldehyde, acetone, and ammonia. The enhanced gas-sensing properties of the Ho-doped ZnO material can be attributed to the fact that the Ho-doping distorts the crystal lattice of the ZnO, increases the specific surface area, and generates a large amount of oxygen defects. In addition, the doped Ho partially forms a Ho2O3/ZnO heterojunction in the material and improves the gas-sensing properties. The 3% Ho-doped ZnO material is expected to be a promising candidate for the trace detection of n-propanol gas.

Predictive value of serum MED1 and PGC-1α for bronchopulmonary dysplasia in preterm infants.

OBJECTIVE: This study aimed to predict the bronchopulmonary dysplasia (BPD) in preterm infants with a gestational age(GA) < 32 weeks utilizing clinical data, serum mediator complex subunit 1 (MED1), and serum peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1α). METHODS: This prospective observational study enrolled 70 preterm infants with GA < 32 weeks. The infants were categorized into two groups: non-BPD group(N = 35) and BPD group(N = 35), including 25 cases with mild BPD and 10 patients with moderate/severe subgroups. We performed multifactorial regression analysis to investigate the postnatal risk factors for BPD. Furthermore, we compared serum levels of biomarkers, including MED1 and PGC-1α, among infants with and without BPD at postnatal days 1, 7, 14, 28, and PMA 36 weeks. A logistic regression model was constructed to predict BPD's likelihood using clinical risk factors and serum biomarkers. RESULTS: Serum levels of MED1 on the first postnatal day, PGC-1α on the 1st, 7th, and 28th days, and PMA at 36 weeks were significantly lower in the BPD group than in the non-BPD group (P < 0.05). Furthermore, the predictive model for BPD was created by combing serum levels of MED1 and PGC-1α on postnatal day 1 along with clinical risk factors such as frequent apnea, mechanical ventilation time > 7 d, and time to reach total enteral nutrition. Our predictive model had a high predictive accuracy(C statistics of 0.989) . CONCLUSION: MED1and PGC-1α could potentially serve as valuable biomarkers, combined with clinical factors, to aid clinicians in the early diagnosis of BPD.

Effects of Cognitive Intervention and Rehabilitation Training on the Expression of miR-134-5p in Elderly Patients with Diabetes Mellitus and Cognitive Impairment.

OBJECTIVE: This study aimed to analyze the effect and potential mechanism of cognitive intervention and rehabilitation training in elderly patients with diabetes mellitus complicated with mild cognitive impairment. METHODS: In this study, 128 elderly patients with diabetes mellitus complicated with mild cognitive impairment were randomly divided into the control group and the training group. The effects of the two groups were compared before and after the cognitive intervention. The expression of miR-134-5p was assessed by qRT-PCR. The relationships between miR-134-5p and Mini-Mental State Examination Scale and Montreal Cognitive Assessment Scale were evaluated. RESULTS: After 3-month management, the Mini-Mental State Examination Scale, Montreal Cognitive Assessment Scale, the Chinese version of the diabetes self-efficacy rating scale, and WHO quality of life brief were improved in both control group and training group, and the training group showed better improvement. Cognitive intervention and rehabilitation training restricted the expression of miR-134-5p. The levels of miR-134-5p were pertinent to cognitive function. CONCLUSION: Cognitive intervention and rehabilitation training might prevent the development of diabetes mellitus complicated with mild cognitive impairment by inhibiting miR-134-5p.

miR-889-3p Facilitates the Browning Process of White Adipocyte Precursors by Targeting the SON Gene.

It is well-established that beige/brown adipose tissue can dissipate stored energy through thermogenesis; hence, the browning of white adipocytes (WAT) has garnered significant interest in contemporary research. Our preceding investigations have identified a marked downregulation of miR-889-3p concurrent with the natural maturation of brown adipose tissue. However, the specific role and underlying molecular mechanisms of miR-889-3p in the browning process of white adipose tissue warrant further elucidation. In this research, we initially delved into the potential role of miR-889-3p in preadipocyte growth via flow cytometry and CCK-8 assay, revealing that miR-889-3p can stimulate preadipocyte growth. To validate the potential contribution of miR-889-3p in the browning process of white adipose tissue, we established an in vitro rabbit white adipocyte browning induction, which exhibited a significant upregulation of miR-889-3p during the browning process. RT-qPCR and Western blot analysis indicated that miR-889-3p overexpression significantly amplified the mRNA levels of UCP1, PRDM16, and CIDEA, as well as UCP1 protein levels. Furthermore, miR-889-3p overexpression fostered intracellular triglyceride accumulation. Conversely, the downregulation of miR-889-3p hindered the browning of rabbit preadipocytes. Subsequently, based on target gene prediction and luciferase reporter gene determination, we demonstrated that miR-889-3p directly targets the 3'-UTR region of SON. Lastly, we observed that inhibiting SON could facilitate the browning of rabbit preadipocytes. In conclusion, our findings suggest that miR-889-3p facilitates the browning process of white adipocyte precursors by specifically targeting the SON gene.

lncRNA MSTRG4710 Promotes the Proliferation and Differentiation of Preadipocytes through miR-29b-3p/IGF1 Axis.

Obesity, a major global health issue, is increasingly associated with the integral role of long non-coding RNA (lncRNA) in adipogenesis. Recently, we found that lncRNA-MSTRG4710 was highly expressed in the liver of rabbits fed a high-fat diet, but whether it is involved in lipid metabolism remains unclear. A series of experiments involving CCK-8, EDU, qPCR, and Oil Red O staining demonstrated that the overexpression of MSTRG4710 stimulated the proliferation and differentiation of preadipocytes while its knockdown inhibited these processes. Bioinformatics analysis showed that miR-29b-3p was a potential target gene of MSTRG4710, and IGF1 was a downstream target gene of miR-29b-3p. Luciferase reporter gene analysis and qPCR analysis confirmed that miR-29b-3p was a potential target gene of MSTRG4710, and miR-29b-3p directly targeted the 3'UTR of IGF1. The overexpression of miR-29b-3p was observed to regulate IGF1 protein and mRNA levels negatively. Additionally, a total of 414 known differentially expressed genes between the miR-29b-3p mimic, miR-29b-3p negative control (NC), siMSTRG4710, and siMSTRG4710-NC group were screened via transcriptome sequencing technology. The GO- and KEGG-enriched pathways were found to be related to lipid metabolism. The study also established that miR-29b-3p targets IGF1 to inhibit preadipocyte proliferation and differentiation. Notably, IGF1 knockdown significantly reduced preadipocyte proliferation and differentiation. Furthermore, co-transfection of pcDNA3.1(+)-MSTRG4710 and mimics into rabbit preadipocytes revealed that the mimics reversed the promotional effect of pcDNA3.1(+)-MSTRG4710. In conclusion, these results uncover that MSTRG4710 positively regulated cell proliferation and adipogenesis by the miR-29b-3p/IGF1 axis. Our findings might provide a new target for studying adipogenesis in rabbit preadipocytes and obesity.

miR-383-5p Regulates Preadipocyte Proliferation and Differentiation by Targeting RAD51AP1.

Obesity has become a major health problem worldwide, and increasing evidence supports the importance of microRNAs (miRNAs) in its pathogenesis. Recently, we found that miR-383-5p_1 is highly expressed in the perirenal fat of high-fat-fed rabbits, but it is not yet known whether miR-383-5p is involved in lipid metabolism. Here, we used transcriptome sequencing technology to screen 1642 known differentially expressed genes between miR-383-5p mimic groups and miR-383-5p negative control groups. Gene Ontology Resource (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were enriched in the pathway related to lipid metabolism, and glycine biosynthesis, the NOD receptor signal pathway and nonalcoholic fatty liver were significantly enriched. Afterwards, our research results indicated that miR-383-5p can promote the proliferation and differentiation of rabbit preadipocytes, and there is a direct targeting relationship with RAD51AP1. Mechanistically, miR-383-5p directly interacts with the lipid metabolism and participates in adipogenesis and lipid accumulation by targeting RAD51AP1. In conclusion, our data highlight a physiological role for miRNA in lipid metabolism and suggest the miR-383-5p/RAD51AP1 axis may represent a potential mechanism for controlling lipid accumulation in obesity.

Integrated analysis of microRNAs, circular RNAs, long non-coding RNAs, and mRNAs revealed competing endogenous RNA networks involved in brown adipose tissue whitening in rabbits.

BACKGROUND: The brown adipose tissue (BAT) is a target for treating obesity. BAT losses thermogenic capacity and gains a "white adipose tissue-like" phenotype ("BAT whitening") under thermoneutral environments, which is a potential factor causing a low curative effect in BAT-related obesity treatments. Circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNA) to mRNAs and function in various processes by sponging shared microRNAs (miRNAs). However, the roles of circRNA- and lncRNA-related ceRNA networks in regulating BAT whitening remain litter known. RESULTS: In this study, BATs were collected from rabbits at day0 (D0), D15, D85, and 2 years (Y2). MiRNA-seq was performed to investigate miRNA changes during BAT whitening. Then, a combined analysis of circRNA-seq and whole-transcriptome sequencing was used for circRNA assembly and quantification during BAT whitening. Our data showed that 1187 miRNAs and 6204 circRNAs were expressed in the samples, and many of which were identified as significantly changed during BAT whitening. Target prediction showed that D0-selective miRNAs were significantly enriched in the Ras, MAPK, and PI3K-Akt signaling pathways, and Y2-selective miRNAs were predicted to be involved in cell proliferation. The cyclization of several circRNAs could form novel response elements of key thermogenesis miRNAs at the back-splicing junction (BSJ) sites, and in combination with a dual-luciferase reporter assay confirmed the binding between the BSJ site of novel_circ_0013792 and ocu-miR-378-5p. CircRNAs and lncRNAs have high cooperativity in sponging miRNAs during BAT whitening. Both circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA triple networks were significantly involved in immune response-associated biological processes. The D15-selective circRNA might promote BAT whitening by increasing the expression of IDH2. The Y2-selective circRNA-related ceRNA network and lncRNA-related ceRNA network might regulate the formation of the WAT-like phenotype of BAT via MAPK and Ras signaling pathways, respectively. CONCLUSIONS: Our work systematically revealed ceRNA networks during BAT whitening in rabbits and might provide new insight into BAT-based obesity treatments.

OsGRETCHENHAGEN3-2 modulates rice seed storability via accumulation of abscisic acid and protective substances.

Seed storability largely determines the vigor of seeds during storage and is significant in agriculture and ecology. However, the underlying genetic basis remains unclear. In the present study, we report the cloning and characterization of the rice (Oryza sativa) indole-3-acetic acid (IAA)-amido synthetase gene GRETCHEN HAGEN3-2 (OsGH3-2) associated with seed storability. OsGH3-2 was identified by performing a genome-wide association study in rice germplasms with linkage mapping in chromosome substitution segment lines, contributing to the wide variation of seed viability in the populations after long periods of storage and artificial ageing. OsGH3-2 was dominantly expressed in the developing seeds and catalyzed IAA conjugation to amino acids, forming inactive auxin. Transgenic overexpression, knockout, and knockdown experiments demonstrated that OsGH3-2 affected seed storability by regulating the accumulation level of abscisic acid (ABA). Overexpression of OsGH3-2 significantly decreased seed storability, while knockout or knockdown of the gene enhanced seed storability compared with the wild-type. OsGH3-2 acted as a negative regulator of seed storability by modulating many genes related to the ABA pathway and probably subsequently late embryogenesis-abundant proteins at the transcription level. These findings shed light on the molecular mechanisms underlying seed storability and will facilitate the improvement of seed vigor by genomic breeding and gene-editing approaches in rice.

Mutant p53 antagonizes p63/p73-mediated tumor suppression via Notch1.

p53 is the most frequently mutated gene in human cancers and mutant p53 has a gain of function (GOF) that promotes tumor progression and therapeutic resistance. One of the major GOF activities of mutant p53 is to suppress 2 other p53 family proteins, p63 and p73. However, the molecular basis is not fully understood. Here, we examined whether mutant p53 antagonizes p63/p73-mediated tumor suppression in vivo by using mutant p53-R270H knockin and TAp63/p73-deficient mouse models. We found that knockin mutant p53-R270H shortened the life span of p73+/- mice and subjected TAp63+/- or p73+/- mice to T lymphoblastic lymphomas (TLBLs). To unravel the underlying mechanism, we showed that mutant p53 formed a complex with Notch1 intracellular domain (NICD) and antagonized p63/p73-mediated repression of HES1 and ECM1. As a result, HES1 and ECM1 were overexpressed in TAp63+/- ;p53R270H/- and p73+/- ;p53R270H/- TLBLs, suggesting that normal function of HES1 and ECM1 in T cell activation is hyperactivated, leading to lymphomagenesis. Together, our data reveal a previously unappreciated mechanism by which GOF mutant p53 hijacks the p63/p73-regulated transcriptional program via the Notch1 pathway.

Natural Variation of Fatty Acid Desaturase Gene Affects Linolenic Acid Content and Starch Pasting Viscosity in Rice Grains.

Rice, as one of the main food crops, provides a vital source of dietary energy for over half the world's population. The OsFAD3 gene encodes fatty acid desaturase, catalyzing the conversion of linoleic acid (LA) to alpha-linolenic acid (ALA) in rice. However, the genetic characterization of OsFAD3 and its role in the conversion of LA to ALA remains elusive. Here, we validated the effects of two homologous genes, OsFAD3-1 and OsFAD3-2, on the ALA and LA/ALA ratio in rice grains using near-isogenic lines. Two major haplotypes of OsFAD3-1 are identified with different effects on the ALA and LA/ALA ratio in rice germplasm. High expression of OsFAD3-1 is associated with high ALA accumulation and eating quality of rice grains. Overexpression of OsFAD3-1 driven by a seed-specific promoter increases the ALA content up to 16-fold in the endosperm. A diagnostic marker is designed based on an 8-bp insertion/deletion in the OsFAD3-1 promoter, which can recognize OsFAD3-1 alleles in rice. These results indicate that OsFAD3-1 is a useful target gene in marker-assisted breeding programs to improve varieties with high ALA and appropriate LA/ALA ratio in brown rice.

Mdm2 is a target and mediator of IRP2 in cell growth control.

Iron is an essential element to all living organisms and plays a vital role in many cellular processes, such as DNA synthesis and energy production. The Mdm2 oncogene is an E3 ligase and known to promote tumor growth. However, the role of Mdm2 in iron homeostasis is not certain. Here, we showed that Mdm2 expression was increased by iron depletion but decreased by iron repletion. We also showed that Iron Regulatory Protein 2 (IRP2) mediated iron-regulated Mdm2 expression. Specifically, Mdm2 expression was increased by ectopic IRP2 but decreased by knockdown or knockout of IRP2 in human cancer cells as well as in mouse embryonic fibroblasts. In addition, we showed that IRP2-regulated Mdm2 expression was independent of tumor suppressor p53. Mechanistically, we found that IRP2 stabilized Mdm2 transcript via binding to an iron response element (IRE) in the 3'UTR of Mdm2 mRNA. Finally, we showed that Mdm2 is required for IRP2-mediated cell proliferation and Mdm2 expression is highly associated with IRP2 in both the normal and cancerous liver tissues. Together, we uncover a novel regulation of Mdm2 by IRP2 via mRNA stability and that the IRP2-Mdm2 axis may play a critical role in cell growth.

FDXR regulates TP73 tumor suppressor via IRP2 to modulate aging and tumor suppression.

Ferredoxin reductase (FDXR) is a mitochondrial flavoprotein that initiates electron transport from NADPH to several cytochromes P450 via two electron carriers, ferredoxin 1 (FDX1) and FDX2. FDXR is the sole ferredoxin reductase in humans and plays a critical role in steroidogenesis and biosynthesis of heme and iron-sulfur clusters. However, much less is known about the role of FDXR in cancer. Here, we show that FDXR plays a role in tumorigenesis by modulating expression of the tumor suppressor p73. By using genetically modified mouse models, we recently showed that mice deficient in either Fdxr or Trp73 had a shorter lifespan and were prone to spontaneous tumors as compared with wild-type (WT) mice. Interestingly, compound Trp73 +/- ;Fdxr +/- mice lived longer and developed fewer tumors when compared with Fdxr +/- or Trp73 +/- mice. Moreover, we found that cellular senescence was increased in Trp73 +/- and Fdxr +/- mouse embryonic fibroblasts (MEFs), which was further increased in Trp73 +/- ;Fdxr +/- MEFs, as compared with that in WT MEFs. As FDXR is regulated by p73, we examined whether there was a feedback regulation between p73 and FDXR. Indeed, we found that Trp73 expression was decreased by loss of Fdxr in MEFs and that FDXR is required for p73 expression in multiple human cancer cell lines independent of p53. Mechanistically, we found that loss of FDXR, via FDX2, increased expression of iron-binding protein 2 (IRP2), which subsequently repressed TP73 mRNA stability. We also showed that TP73 transcript contained an iron response element in its 3'UTR, which was required for IRP2 to destabilize TP73 mRNA. Together, these data reveal a novel regulation of p73 by FDXR via IRP2 and that the FDXR-p73 axis plays a critical role in aging and tumor suppression. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Rice SPL10 positively regulates trichome development through expression of HL6 and auxin-related genes.

Trichomes function in plant defenses against biotic and abiotic stresses; examination of glabrous lines, which lack trichomes, has revealed key aspects of trichome development and function. Tests of allelism in 51 glabrous rice (Oryza sativa) accessions collected worldwide identified OsSPL10 and OsWOX3B as regulators of trichome development in rice. Here, we report that OsSPL10 acts as a transcriptional regulator controlling trichome development. Haplotype and transient expression analyses revealed that variation in the approximately 700-bp OsSPL10 promoter region is the primary cause of the glabrous phenotype in the indica cultivar WD-17993. Disruption of OsSPL10 by genome editing decreased leaf trichome density and length in the NIL-HL6 background. Plants with genotype OsSPL10WD-17993 /HL6 generated by crossing WD-17993 with NIL-HL6 also had fewer trichomes in the glumes. HAIRY LEAF6 (HL6) encodes another transcription factor that regulates trichome initiation and elongation, and OsSPL10 directly binds to the HL6 promoter to regulate its expression. Moreover, the transcript levels of auxin-related genes, such as OsYUCCA5 and OsPIN-FORMED1b, were altered in OsSPL10 overexpression and RNAi transgenic lines. Feeding tests using locusts (Locusta migratoria) demonstrated that non-glandular trichomes affect feeding by this herbivore. Our findings provide a molecular framework for trichome development and an ecological perspective on trichome functions.

Serine 195 phosphorylation in the RNA-binding protein Rbm38 increases p63 expression by modulating Rbm38's interaction with the Ago2-miR203 complex.

The p63 transcription factor, a p53 family protein, regulates genes involved in various cellular processes, including cell growth and differentiation. We previously showed that RNA-binding motif protein (Rbm38) is a p63 target and, in turn, regulates p63α mRNA stability by binding to the AU/U-rich element in its 3'UTR. Interestingly, Rbm38 can be phosphorylated at serine 195, altering its ability to regulate mRNA translation. However, whether the Ser-195 phosphorylation affects Rbm38's ability to destabilize p63 mRNA remains unclear. Here, using MCF7 and HaCaT cells, we showed that ectopic expression of phosphomimetic Rbm38-S195D increases, whereas WT Rbm38 and nonphosphorylatable Rbm38-S195A decrease p63α protein and transcript levels. We also found that upon activation of glycogen synthase kinase 3ß (GSK3ß), phosphorylation of Rbm38 at Ser-195 is increased, enhancing p63α expression in an Rbm38-dependent manner. To confirm this, we generated mouse embryo fibroblasts (MEFs) in which Ser-193 in mouse Rbm38 (equivalent to Ser-195 in human Rbm38) was substituted with aspartic acid (Rbm38S193D/S193D ) or alanine (Rbm38S193A/S193A ). We observed that the p63 transcript level was increased in Rbm38S193D/S193D MEFs, but decreased in Rbm38S193A/S193A MEFs. Mechanistically, we found that WT Rbm38, but not Rbm38-S195D, is required for p63 mRNA degradation mediated by microRNA 203 (miR203). Furthermore, we noted that Argonaute 2 (Ago2), a key regulator in microRNA-mediated mRNA decay, associates with WT Rbm38, and this association was reduced by Ser-195 phosphorylation. Together, our results reveal a critical mechanism by which Ser-195 phosphorylation in Rbm38 increases p63 expression by attenuating the association of Rbm38 with the Ago2-miR203 complex.

Molecular evolution of the ATP-binding cassette subfamily G member 2 gene subfamily and its paralogs in birds.

BACKGROUND: ATP-binding cassette (ABC) transporters are involved in the active transportation of various endogenous or exogenous substances. Two ABCG2 gene subfamily members have been identified in birds. A detailed comparative study of the ABCG2 and ABCG2-like genes aid our understanding of their evolutionary history at the molecular level and provide a theoretical reference for studying the specific functions of ABCG2 and ABCG2-like genes in birds. RESULTS: We first identified 77 ABCG2/ABCG2-like gene sequences in the genomes of 41 birds. Further analysis showed that both the nucleic acid and amino acid sequences of ABCG2 and ABCG2-like genes were highly conserved and exhibited high homology in birds. However, significant differences in the N-terminal structure were found between the ABCG2 and ABCG2-like amino acid sequences. A selective pressure analysis showed that the ABCG2 and ABCG2-like genes were affected by purifying selection during the process of bird evolution. CONCLUSIONS: We believe that multiple members of the ABCG2 gene subfamily exist on chromosome 4 in the ancestors of birds. Over the long course of evolution, only the ABCG2 gene was retained on chromosome 4 in birds. The ABCG2-like gene on chromosome 6 might have originated from chromosome replication or fusion. The structural differences between the N terminus of ABCG2 protein and those of ABCG2-like proteins might lead to functional differences between the corresponding genes.

Metabolome Analysis of Multi-Connected Biparental Chromosome Segment Substitution Line Populations.

Metabolomic analysis coupled with advanced genetic populations represents a powerful tool with which to investigate the plant metabolome. However, genetic analyses of the rice (Oryza sativa) metabolome have been conducted mainly using natural accessions or a single biparental population. Here, the flag leaves from three interconnected chromosome segment substitution line populations with a common recurrent genetic background were used to dissect rice metabolic diversity. We effectively used multiple interconnected biparental populations, constructed by introducing genomic segments into Zhenshan 97 from ACC10 (A/Z), Minghui 63 (M/Z), and Nipponbare (N/Z), to map metabolic quantitative trait loci (mQTL). A total of 1,587 mQTL were generated, of which 684, 479, and 722 were obtained from the A/Z, M/Z, and N/Z chromosome segment substitution line populations, respectively, and we designated 99 candidate genes for 367 mQTL. In addition, 1,001 mQTL were generated specifically from joint linkage analysis with 25 candidate genes assigned. Several of these candidates were validated, such as LOC_Os07g01020 for the in vivo content of pyridoxine and its derivative and LOC_Os04g25980 for cis-zeatin glucosyltransferase activity. We propose a novel biosynthetic pathway for O-methylapigenin C-pentoside and demonstrated that LOC_Os04g11970 encodes a component of this pathway through fine-mapping. We postulate that the methylated apigenin may confer plant disease resistance. This study demonstrates the power of using multiple interconnected populations to generate a large number of veritable mQTL. The combined results are discussed in the context of functional metabolomics and the possible features of assigned candidates underlying respective metabolites.