Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins ...Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.展开更多
Objective: To explore the effects of nuclear M-CSF on the process of tumorigenesis. Methods: Functional part of M-CSF cDNA was inserted into an eukaryotic expression plasmid pCMV/myc/nuc, which can add three NLS to t...Objective: To explore the effects of nuclear M-CSF on the process of tumorigenesis. Methods: Functional part of M-CSF cDNA was inserted into an eukaryotic expression plasmid pCMV/myc/nuc, which can add three NLS to the C-terminal of the expressed protein and direct the protein into the cell nuclei. The constructed plasmid was transferred into NIH3T3 cells and the cell clones were selected by G-418 selection. Cell clones stable expressing target protein were identified by RT-PCR, ABC immunohistochemistry assayand Western blot. Cell growth kinetics analyses throughgrowth curves, cell doubling time, MTT test and anti-sense oligodeoxynucleotide (ASODN) inhibiting cell growth testwere performed to identify cells proliferation potential.Results: The transfected cells showed elevated proliferation potential over the control cells. Conclusion: Abnormalappearance of M-CSF in nucleus could enhance cellproliferation, which suggests that cytokine isoforms within cell nucleus might play transcription factor-like role.展开更多
Human SAMHD1(h SAM)restricts lentiviruses at the reverse transcription step through its d NTP triphosphohydrolase(d NTPase)activity.Besides humans,several mammalian species such as cats and cows that carry their own l...Human SAMHD1(h SAM)restricts lentiviruses at the reverse transcription step through its d NTP triphosphohydrolase(d NTPase)activity.Besides humans,several mammalian species such as cats and cows that carry their own lentiviruses also express SAMHD1.However,the intracellular distribution of feline and bovine SAMHD1(f SAM and b SAM)and its significance in their lentiviral restriction function is not known.Here,we demonstrated that f SAM and b SAM were both predominantly localized to the nucleus and nuclear localization signal(11KRPR14)-deleted f SAM and b SAM relocalized to the cytoplasm.Both cytoplasmic f SAM and b SAM retained the antiviral function against different lentiviruses and cytoplasmic f SAM could restrict Vpx-encoding SIV and HIV-2 more efficiently than its wild-type(WT)protein as cytoplasmic h SAM.Further investigation revealed that cytoplasmic f SAM was resistant to Vpx-induced degradation like cytoplasmic h SAM,while cytoplasmic b SAM was not,but they all demonstrated the same in vitro d NTPase activity and all could interact with Vpx as their WT proteins,indicating that cytoplasmic h SAM and f SAM can suppress more SIV and HIV-2 by being less sensitive to Vpx-mediated degradation.Our results suggested that f SAM-and b SAM-mediated lentiviral restriction does not require their nuclear localization and that f SAM shares more common features with h SAM.These findings may provide insights for the establishment of alternative animal models to study SAMHD1 in vivo.展开更多
We prove the asymptotic stability of solitary waves to 1D nonlinear Schrodinger equations in the subcritical case with symmetry and spectrum assumptions.One of the main ideas is to use the vector fields method develop...We prove the asymptotic stability of solitary waves to 1D nonlinear Schrodinger equations in the subcritical case with symmetry and spectrum assumptions.One of the main ideas is to use the vector fields method developed by S.Cuccagna,V.Georgiev,and N.Visciglia[Comm.Pure Appl.Math.,2013,6:957-980]to overcome the weak decay with respect to t of the linearized equation caused by the one dimension setting and the weak nonlinearity caused by the subcritical growth of the nonlinearity term.Meanwhile,we apply the polynomial growth of the high Sobolev norms of solutions to 1D Schrodinger equations obtained by G.Staffilani[Duke Math.J.,1997,86(1):109-142]to control the high moments of the solutions emerging from the vector fields method.展开更多
基金Supported by the National Natural Science Foundation of China(No.31970429)the Shandong Provincial Natural Science Foundation(No.ZR 2022 MC 032)。
文摘Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.
基金This work was supported by a grant from Tianjin Science and Technology Development Project (No. 003119311).
文摘Objective: To explore the effects of nuclear M-CSF on the process of tumorigenesis. Methods: Functional part of M-CSF cDNA was inserted into an eukaryotic expression plasmid pCMV/myc/nuc, which can add three NLS to the C-terminal of the expressed protein and direct the protein into the cell nuclei. The constructed plasmid was transferred into NIH3T3 cells and the cell clones were selected by G-418 selection. Cell clones stable expressing target protein were identified by RT-PCR, ABC immunohistochemistry assayand Western blot. Cell growth kinetics analyses throughgrowth curves, cell doubling time, MTT test and anti-sense oligodeoxynucleotide (ASODN) inhibiting cell growth testwere performed to identify cells proliferation potential.Results: The transfected cells showed elevated proliferation potential over the control cells. Conclusion: Abnormalappearance of M-CSF in nucleus could enhance cellproliferation, which suggests that cytokine isoforms within cell nucleus might play transcription factor-like role.
基金funded by the National Natural Science Foundation of China(31270807)the Key Projects in the National Science&Technology Pillar Program in the Thirteenth Five-year Plan Period(2018ZX10731101-002-003 and 2018ZX10731101-001-020)+3 种基金Program for Jilin University Science and Technology Innovative Research Team(JLUSTIRT)(2017TD05)National Postdoctoral Program for Innovative Talents(BX20180124)China Postdoctoral Science Foundation(2018M641786)Science and Technology Development Project of Jilin Province(20200901030SF)。
文摘Human SAMHD1(h SAM)restricts lentiviruses at the reverse transcription step through its d NTP triphosphohydrolase(d NTPase)activity.Besides humans,several mammalian species such as cats and cows that carry their own lentiviruses also express SAMHD1.However,the intracellular distribution of feline and bovine SAMHD1(f SAM and b SAM)and its significance in their lentiviral restriction function is not known.Here,we demonstrated that f SAM and b SAM were both predominantly localized to the nucleus and nuclear localization signal(11KRPR14)-deleted f SAM and b SAM relocalized to the cytoplasm.Both cytoplasmic f SAM and b SAM retained the antiviral function against different lentiviruses and cytoplasmic f SAM could restrict Vpx-encoding SIV and HIV-2 more efficiently than its wild-type(WT)protein as cytoplasmic h SAM.Further investigation revealed that cytoplasmic f SAM was resistant to Vpx-induced degradation like cytoplasmic h SAM,while cytoplasmic b SAM was not,but they all demonstrated the same in vitro d NTPase activity and all could interact with Vpx as their WT proteins,indicating that cytoplasmic h SAM and f SAM can suppress more SIV and HIV-2 by being less sensitive to Vpx-mediated degradation.Our results suggested that f SAM-and b SAM-mediated lentiviral restriction does not require their nuclear localization and that f SAM shares more common features with h SAM.These findings may provide insights for the establishment of alternative animal models to study SAMHD1 in vivo.
文摘We prove the asymptotic stability of solitary waves to 1D nonlinear Schrodinger equations in the subcritical case with symmetry and spectrum assumptions.One of the main ideas is to use the vector fields method developed by S.Cuccagna,V.Georgiev,and N.Visciglia[Comm.Pure Appl.Math.,2013,6:957-980]to overcome the weak decay with respect to t of the linearized equation caused by the one dimension setting and the weak nonlinearity caused by the subcritical growth of the nonlinearity term.Meanwhile,we apply the polynomial growth of the high Sobolev norms of solutions to 1D Schrodinger equations obtained by G.Staffilani[Duke Math.J.,1997,86(1):109-142]to control the high moments of the solutions emerging from the vector fields method.
