Objective:The E3 ligase,CRL4,plays diverse roles in different cellular processes,such as DNA damage,transcriptional regulation,cell cycle progression,and cell apoptosis.Our previous study showed that CUL4A and CUL4B h...Objective:The E3 ligase,CRL4,plays diverse roles in different cellular processes,such as DNA damage,transcriptional regulation,cell cycle progression,and cell apoptosis.Our previous study showed that CUL4A and CUL4B had a strong association with tobacco smoking risk in lung squamous cell carcinoma(SCC)and small cell lung carcinoma(SCLC).This study aimed to define the potential mechanism underlying the roles of CUL4A and CUL4B in the development of SCC and SCLC.Methods:We determined the role of CUL4A and CUL4B in the cell cycle and apoptosis of SCC and SCLC,and identified the key apoptosis-related gene involved in the oncogenic activity of CUL4B by Western blot,immunohistochemical staining,flow cytometry,and enzyme inhibition experiments.Results:We found that depletion of CUL4A and CUL4B reduced the proliferation of SCC and SCLC cells.cUL4Aknockdown but not CUL4Bknockdown arrested cells in Gl phase while upregulating P21 and cU L4Bknockdown promoted cell apoptosis through upregulation o f FOXO3A.Accordingly,CUL4B decreased FO X03A expression by activating the ERK signaling pathway and mediating FOXO3A degradation via the ubiquitin-proteasome pathway.Conclusions:These results identified the function of E3 ligase CRL4 in regulating SCC and SCLC cell proliferation,which provides a potential strategy for cancer therapy by targeting FOXO3A and the E3 ligase,CRL4.展开更多
Aim:To identify genes related to the human testis development by substrate hybridization technique.Methods:A human testis cDNA microarray was constructed and hybridized with probes prepared from human adult and fetal ...Aim:To identify genes related to the human testis development by substrate hybridization technique.Methods:A human testis cDNA microarray was constructed and hybridized with probes prepared from human adult and fetal testes and spermatozoa mRNAs by reverse transcription reactions.The differentially expressed genes were sequenced. And a newly identified cullin-3 (CUL-3) transcript variant (designated cul-3b) was bio-informatically analyzed with an online GenBank database.Multi-tissue reverse transcription polymerase chain reaction (RT-PCR) was used to deter- mine the tissue expression profile of cul-3b.Results:Cul-3b,a novel CUL-3 transcript variant,was identified.The expression level of cul-3b in adult testes was 3.79-fold higher than that in fetal ones.Cul-3b differed from cul-3 (including NM_003590 and AY337761) in the opening reading frame and had three internal ribosomal entry sites (IRESes) in the 5'-UTR.These led to a 24 amino acid (aa) truncation at N-terminus of CUL-3b as compared with CUL-3 and a more motivated expression pattern of cul-3b under some strict circumstances.Additionally,cul-3b expressed ubiquitously in human tissues according to multi-tissue RT-PCR.Conclusion:Cul-3b is a novel transcript variant of CUL-3,which may be important not only for the development of human testis but also for that of other organs.展开更多
BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,...BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,long tubular bones,and high vertebral bodies but generally lack mental abnormalities or other organ damage.Pathogenic genes associated with 3M syndrome include CUL7,OBSL1 and CCDC8.The clinical and molecular characteristics of patient with 3M syn-drome are unique and serve as important diagnostic indicators.CASE SUMMARY In this case,the patient displayed square shoulders,scoliosis,long slender tubular bones,and normal neurological development.Notably,the patient did not exhibit the typical dysmorphic facial features,relative macrocephaly,or growth retardation commonly observed in individuals with 3M syndrome.Whole exon sequencing revealed a novel heterozygous c.56681+1G>C(Splice-3)variant and a previously reported nonsense heterozygous c.3341G>A(p.Trp1114Ter)variant of OBSL1.Therefore,it is important to note that the clinical features of 3M syndrome may not always be observable,and genetic confirmation is often required.Additionally,the identification of the c.5683+1G>C variant in OBSL1 is notewor-thy because it has not been previously reported in public databases.CONCLUSION Our study identified a new variant(c.5683+1G>C)of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.展开更多
The self imaging effect in graded index waveguides using annealed proton exchange (APE) technique in lithium niobate (LiNbO 3) waveguides is analyzed and simulated using the three dimensional nonparaxial beam pro...The self imaging effect in graded index waveguides using annealed proton exchange (APE) technique in lithium niobate (LiNbO 3) waveguides is analyzed and simulated using the three dimensional nonparaxial beam propagation method (BPM).On this basis,a 1×8 multimode interference (MMI) optical power splitter by APE technique in X cut LiNibO 3 with Y propagation substrate is fabricated.Measurements show that the device has realized eight powers splittings.展开更多
Ambient temperature affects flowering time in plants,and the MADS-box transcription factor SHORT VEGETATIVE PHASE(SVP)plays a crucial role in the response to changes in ambient temperature.SVP protein stability is reg...Ambient temperature affects flowering time in plants,and the MADS-box transcription factor SHORT VEGETATIVE PHASE(SVP)plays a crucial role in the response to changes in ambient temperature.SVP protein stability is regulated by the 26S proteasome pathway and decreases at high ambient temperature,but the details of SVP degradation are unclear.Here,we show that SVP degradation at high ambient temperature is mediated by the CULLIN3–RING E3 ubiquitin ligase(CRL3)complex in Arabidopsis thaliana.We identified a previously uncharacterized protein that interacts with SVP at high ambient temperature and contains a BTB/POZ domain.We named this protein LATE FLOWERING AT HIGH TEMPERATURE 1(LFH1).Single mutants of LFH1 or CULLIN3A(CUL3A)showed late flowering specifically at 27C.LFH1 protein levels increased at high ambient temperature.We found that LFH1 interacts with CUL3A in the cytoplasm and is important for SVP–CUL3A complex formation.Mutations in CUL3A and/or LFH1 led to increased SVP protein stability at high ambient temperature,suggesting that the CUL3–LFH1 complex functions in SVP degradation.Screening E2 ubiquitin-conjugating enzymes(UBCs)using RING-BOX PROTEIN 1(RBX1),a component of the CRL3 complex,as bait identified UBC15.ubc15 mutants also showed late flowering at high ambient temperature.In vitro and in vivo ubiquitination assays using recombinant CUL3A,LFH1,RBX1,and UBC15 showed that SVP is highly ubiquitinated in an ATP-dependent manner.Collectively,these results indicate that the degradation of SVP at high ambient temperature is mediated by a CRL3 complex comprising CUL3A,LFH1,and UBC15.展开更多
Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 l...Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 ligases to mark specific proteins for degradation. In this work, MYB56 is identified as a novel target of a CULLIN3 （CUL3）-based E3 ligase. Its stability depends on the presence of MATH-BTB/POZ （BPM） proteins, which function as substrate adaptors to the E3 ligase. Genetic studies have indicated that MYB56 is a negative regulator of flowering, while BPMs positively affect this developmental program. The interaction between BPMs and MYB56 occurs at the promoter of FLOWERING LOCUS T （FT）, a key regulator in initiating flowering in Arabidopsis, and results in instability of MYB56. Overall the work establishes MYB transcription factors as substrates of BPM proteins, and provides novel information on components that participate in controlling flowering time in plants.展开更多
Flowering time is crucial for successful reproduction in plants, the onset and progression of which are strictly controlled. However, flowering time is a complex and environmentally responsive history trait and the un...Flowering time is crucial for successful reproduction in plants, the onset and progression of which are strictly controlled. However, flowering time is a complex and environmentally responsive history trait and the underlying mechanisms still need to be fully characterized. Post-translational regulation of the activities of transcription factors(TFs) is a dynamic and essential mechanism for plant growth and development. CRL3 BPME3 ligase is a CULLIN3-based E3 ligase involved in orchestrating protein stability via the ubiquitin proteasome pathway. Our study shows that the mutation of MYB106 induced early flowering phenotype while over-expression of MYB106 delayed Arabidopsis flowering. Transcriptome analysis of myb106 mutants reveals 257 differentially expressed genes between wild type and myb106-1 mutants, including Flowering Locus T(FT) which is related to flowering time. Moreover, in vitro electrophoretic mobility shift assays(EMSA), in vivo chromatin immunoprecipitation quantitative polymerase chain reaction(ChIP-q PCR) assays and dual luciferase assays demonstrate that MYB106 directly binds to the promoter of FT to suppress its expression. Furthermore, we confirm that MYB106 interacts with BPM proteins which are further identified by CRL3 BPME3 ligases as the substrate. Taken together, we have identified MYB106 as a negative regulator in the control of flowering time and a new substrate for CRL3 BPM E3 ligases in Arabidopsis.展开更多
基金The National Natural Science Foundation of China(Grant No.81772620 and 31471341)the Key Science and Technology Project of Tianjin Chronic Disease Prevention and Control(Grant No.17XXMFSY00130)the National Science and Technology Major Project(Grant No.2018ZX09201-015).
文摘Objective:The E3 ligase,CRL4,plays diverse roles in different cellular processes,such as DNA damage,transcriptional regulation,cell cycle progression,and cell apoptosis.Our previous study showed that CUL4A and CUL4B had a strong association with tobacco smoking risk in lung squamous cell carcinoma(SCC)and small cell lung carcinoma(SCLC).This study aimed to define the potential mechanism underlying the roles of CUL4A and CUL4B in the development of SCC and SCLC.Methods:We determined the role of CUL4A and CUL4B in the cell cycle and apoptosis of SCC and SCLC,and identified the key apoptosis-related gene involved in the oncogenic activity of CUL4B by Western blot,immunohistochemical staining,flow cytometry,and enzyme inhibition experiments.Results:We found that depletion of CUL4A and CUL4B reduced the proliferation of SCC and SCLC cells.cUL4Aknockdown but not CUL4Bknockdown arrested cells in Gl phase while upregulating P21 and cU L4Bknockdown promoted cell apoptosis through upregulation o f FOXO3A.Accordingly,CUL4B decreased FO X03A expression by activating the ERK signaling pathway and mediating FOXO3A degradation via the ubiquitin-proteasome pathway.Conclusions:These results identified the function of E3 ligase CRL4 in regulating SCC and SCLC cell proliferation,which provides a potential strategy for cancer therapy by targeting FOXO3A and the E3 ligase,CRL4.
文摘Aim:To identify genes related to the human testis development by substrate hybridization technique.Methods:A human testis cDNA microarray was constructed and hybridized with probes prepared from human adult and fetal testes and spermatozoa mRNAs by reverse transcription reactions.The differentially expressed genes were sequenced. And a newly identified cullin-3 (CUL-3) transcript variant (designated cul-3b) was bio-informatically analyzed with an online GenBank database.Multi-tissue reverse transcription polymerase chain reaction (RT-PCR) was used to deter- mine the tissue expression profile of cul-3b.Results:Cul-3b,a novel CUL-3 transcript variant,was identified.The expression level of cul-3b in adult testes was 3.79-fold higher than that in fetal ones.Cul-3b differed from cul-3 (including NM_003590 and AY337761) in the opening reading frame and had three internal ribosomal entry sites (IRESes) in the 5'-UTR.These led to a 24 amino acid (aa) truncation at N-terminus of CUL-3b as compared with CUL-3 and a more motivated expression pattern of cul-3b under some strict circumstances.Additionally,cul-3b expressed ubiquitously in human tissues according to multi-tissue RT-PCR.Conclusion:Cul-3b is a novel transcript variant of CUL-3,which may be important not only for the development of human testis but also for that of other organs.
文摘BACKGROUND A rare autosomal recessive genetic disorder,3M syndrome,is characterized by severe intrauterine and postnatal growth retardation.Children with 3M syndrome typically exhibit short stature,facial deformities,long tubular bones,and high vertebral bodies but generally lack mental abnormalities or other organ damage.Pathogenic genes associated with 3M syndrome include CUL7,OBSL1 and CCDC8.The clinical and molecular characteristics of patient with 3M syn-drome are unique and serve as important diagnostic indicators.CASE SUMMARY In this case,the patient displayed square shoulders,scoliosis,long slender tubular bones,and normal neurological development.Notably,the patient did not exhibit the typical dysmorphic facial features,relative macrocephaly,or growth retardation commonly observed in individuals with 3M syndrome.Whole exon sequencing revealed a novel heterozygous c.56681+1G>C(Splice-3)variant and a previously reported nonsense heterozygous c.3341G>A(p.Trp1114Ter)variant of OBSL1.Therefore,it is important to note that the clinical features of 3M syndrome may not always be observable,and genetic confirmation is often required.Additionally,the identification of the c.5683+1G>C variant in OBSL1 is notewor-thy because it has not been previously reported in public databases.CONCLUSION Our study identified a new variant(c.5683+1G>C)of OBSL1 that contributes to expanding the molecular profile of 3M syndrome.
文摘The self imaging effect in graded index waveguides using annealed proton exchange (APE) technique in lithium niobate (LiNbO 3) waveguides is analyzed and simulated using the three dimensional nonparaxial beam propagation method (BPM).On this basis,a 1×8 multimode interference (MMI) optical power splitter by APE technique in X cut LiNibO 3 with Y propagation substrate is fabricated.Measurements show that the device has realized eight powers splittings.
基金supported by grants from the National Research Foundation of Korea (NRF-2022R1A3B1078180 and RS-2023-00221182 to J.H.A.and NRF-2022R1A2B5B02001266 to P.J.S.).
文摘Ambient temperature affects flowering time in plants,and the MADS-box transcription factor SHORT VEGETATIVE PHASE(SVP)plays a crucial role in the response to changes in ambient temperature.SVP protein stability is regulated by the 26S proteasome pathway and decreases at high ambient temperature,but the details of SVP degradation are unclear.Here,we show that SVP degradation at high ambient temperature is mediated by the CULLIN3–RING E3 ubiquitin ligase(CRL3)complex in Arabidopsis thaliana.We identified a previously uncharacterized protein that interacts with SVP at high ambient temperature and contains a BTB/POZ domain.We named this protein LATE FLOWERING AT HIGH TEMPERATURE 1(LFH1).Single mutants of LFH1 or CULLIN3A(CUL3A)showed late flowering specifically at 27C.LFH1 protein levels increased at high ambient temperature.We found that LFH1 interacts with CUL3A in the cytoplasm and is important for SVP–CUL3A complex formation.Mutations in CUL3A and/or LFH1 led to increased SVP protein stability at high ambient temperature,suggesting that the CUL3–LFH1 complex functions in SVP degradation.Screening E2 ubiquitin-conjugating enzymes(UBCs)using RING-BOX PROTEIN 1(RBX1),a component of the CRL3 complex,as bait identified UBC15.ubc15 mutants also showed late flowering at high ambient temperature.In vitro and in vivo ubiquitination assays using recombinant CUL3A,LFH1,RBX1,and UBC15 showed that SVP is highly ubiquitinated in an ATP-dependent manner.Collectively,these results indicate that the degradation of SVP at high ambient temperature is mediated by a CRL3 complex comprising CUL3A,LFH1,and UBC15.
文摘Controlled stability of proteins is a highly efficient mechanism to direct diverse processes in living cells. A key regulatory system for protein stability is given by the ubiquitin proteasome pathway, which uses E3 ligases to mark specific proteins for degradation. In this work, MYB56 is identified as a novel target of a CULLIN3 （CUL3）-based E3 ligase. Its stability depends on the presence of MATH-BTB/POZ （BPM） proteins, which function as substrate adaptors to the E3 ligase. Genetic studies have indicated that MYB56 is a negative regulator of flowering, while BPMs positively affect this developmental program. The interaction between BPMs and MYB56 occurs at the promoter of FLOWERING LOCUS T （FT）, a key regulator in initiating flowering in Arabidopsis, and results in instability of MYB56. Overall the work establishes MYB transcription factors as substrates of BPM proteins, and provides novel information on components that participate in controlling flowering time in plants.
基金supported by National Natural Science Foundation of China(31670179,and 91854201)the Research Grants Council of Hong Kong(Ao E/M-05/12,CUHK14104716,and C4002-17G)to L.J.+1 种基金RGC(CUHK14104716)CUHK Direct Grants(4053143,4053174,4053243)to L.C.
文摘Flowering time is crucial for successful reproduction in plants, the onset and progression of which are strictly controlled. However, flowering time is a complex and environmentally responsive history trait and the underlying mechanisms still need to be fully characterized. Post-translational regulation of the activities of transcription factors(TFs) is a dynamic and essential mechanism for plant growth and development. CRL3 BPME3 ligase is a CULLIN3-based E3 ligase involved in orchestrating protein stability via the ubiquitin proteasome pathway. Our study shows that the mutation of MYB106 induced early flowering phenotype while over-expression of MYB106 delayed Arabidopsis flowering. Transcriptome analysis of myb106 mutants reveals 257 differentially expressed genes between wild type and myb106-1 mutants, including Flowering Locus T(FT) which is related to flowering time. Moreover, in vitro electrophoretic mobility shift assays(EMSA), in vivo chromatin immunoprecipitation quantitative polymerase chain reaction(ChIP-q PCR) assays and dual luciferase assays demonstrate that MYB106 directly binds to the promoter of FT to suppress its expression. Furthermore, we confirm that MYB106 interacts with BPM proteins which are further identified by CRL3 BPME3 ligases as the substrate. Taken together, we have identified MYB106 as a negative regulator in the control of flowering time and a new substrate for CRL3 BPM E3 ligases in Arabidopsis.
