Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In t...Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.展开更多
Induced pluripotent stem cells are powerful tools for disease modeling,drug screening,and cell transplantation therapies.These cells can be generated directly from somatic cells by ectopic expression of defined factor...Induced pluripotent stem cells are powerful tools for disease modeling,drug screening,and cell transplantation therapies.These cells can be generated directly from somatic cells by ectopic expression of defined factors through a reprogramming process.However,pluripotent reprogramming is an inefficient process because of various defined and unidentified barriers.Recent studies dissecting the molecular mechanisms of reprogramming have methodically improved the quality,ease,and efficiency of reprogramming.Different strategies have been applied for enhancing reprogramming efficiency,including depletion/inhibition of barriers(p53,p21,p57,p16Ink4a/p19Arf,Mbd3,etc.),overexpression of enhancing genes(e.g.,FOXH1,C/EBP alpha,UTF1,and GLIS1),and administration of certain cytokines and small molecules.The current review provides an in-depth overview of the cutting-edge findings regarding distinct barriers of reprogramming to pluripotency and strategies to enhance reprogramming efficiency.By incorporating the mechanistic insights from these recent findings,a combined method of inhibition of roadblocks and application of enhancing factors may yield the most reliable and effective approach in pluripotent reprogramming.展开更多
基金funded by the National Natural Sci-ence Foundation of China,grant numbers 32100374 and 31872286.
文摘Methyl-CpG(mCpG)binding domain(MBD)proteins especially bind with methylated DNA,and are involved in many important biological processes;however,the binding mechanism between insect MBD2/3 and mCpG remains unclear.In this study,we identified 2 isoforms of the MBD2/3 gene in Bombyx mori,MBD2/3-S and MBD2/3-L.Binding analysis of MBD2/3-L,MBD2/3-S,and 7 mutant MBD2/3-L proteins deficient inβ1−β6 orα1 in the MBD showed thatβ2−β3-turns in theβ-sheet of the MBD are necessary for the formation of the MBD2/3–mCpG complex;furthermore,other secondary structures,namely,β4−β6 and anα-helix,play a role in stabilizing theβ-sheet structure to ensure that the MBD is able to bind mCpG.In addition,sequence alignment and binding analyses of different insect MBD2/3s indicated that insect MBD2/3s have an intact and conserved MBD that binds to the mCpG of target genes.Furthermore,MBD2/3 RNA interference results showed that MBD2/3-L plays a role in regulating B.mori embryonic development,similar to that of DNA methylation;however,MBD2/3-S withoutβ4−β6 andα-helix does not alter embryonic development.These results suggest that MBD2/3-L recognizes and binds to mCpG through the intactβ-sheet structure in its MBD,thus ensuring silkworm embryonic development.
基金This work is supported by the Yazd Cardiovascular Research Center (YCRC).
文摘Induced pluripotent stem cells are powerful tools for disease modeling,drug screening,and cell transplantation therapies.These cells can be generated directly from somatic cells by ectopic expression of defined factors through a reprogramming process.However,pluripotent reprogramming is an inefficient process because of various defined and unidentified barriers.Recent studies dissecting the molecular mechanisms of reprogramming have methodically improved the quality,ease,and efficiency of reprogramming.Different strategies have been applied for enhancing reprogramming efficiency,including depletion/inhibition of barriers(p53,p21,p57,p16Ink4a/p19Arf,Mbd3,etc.),overexpression of enhancing genes(e.g.,FOXH1,C/EBP alpha,UTF1,and GLIS1),and administration of certain cytokines and small molecules.The current review provides an in-depth overview of the cutting-edge findings regarding distinct barriers of reprogramming to pluripotency and strategies to enhance reprogramming efficiency.By incorporating the mechanistic insights from these recent findings,a combined method of inhibition of roadblocks and application of enhancing factors may yield the most reliable and effective approach in pluripotent reprogramming.
