Design of Lipophilic Split Aptamers as Artificial Carriers for Transmembrane Transport of Adenosine Triphosphate

Transmembrane transport plays an important role in many physiological functions,and mimicking this biological process in artificial systems has potential applications in biosensing,drug delivery,and bionic science.Here,a lipophilic split aptamer was developed as a novel transmembrane carrier for adenosine triphosphate(ATP)transport.The ATP carrier comprises two split aptamer fragments and cholesterol tags,with the split aptamers acting as targetrecognition domains to enhance their specific binding capability and the cholesterol tags as hydrophobic domains to facilitate membrane penetration.Giant unilamellar vesicle experiments demonstrated that the ATP carrier-mediated transmembrane transport was concentration-and time-dependent and showed high transport selectivity.Moreover,the artificial carriers were applicable to living cells and facilitated rapid cell internalization of fluorescencelabeled ATP.Furthermore,carrier-mediated ATP transport into ATP-deficient cells enabled recovery of cellular ATP levels and improved cell viability.This study demonstrated the efficacy of an aptamer nanostructure for designing DNA-based synthetic carriers with high selectivity and flexibility.

BcSDR1 is involved in regulation of glucose transport and cAMP and MAPK signaling pathways in Botrytis cinerea

Botrytis cinerea is a typical necrotrophic pathogenic fungus that causes severe diseases in a wide range of plant species, leading to significant economic losses. Our previous study showed that BcSDR1 positively regulates growth,development, and pathogenicity of B. cinerea. However, the regulation mechanism of BcSDR1 and the relationship between BcSDR1 and cAMP and MAPK signaling pathways are not well understood. In this study, transcriptome data showed that BcSDR1 is involved in glucose transmembrane transport, signal transduction, secondary metabolism, and other biological processes. BcSDR1 mutant(BCt41) showed remarkably weak sensitivity to cAMP and MAPK signaling pathways specific inhibitors, SQ22536 and U0126, and significantly decreased cAMP content. The key genes of cAMP and MAPK signaling pathways, BcGB1, BcBTP1, BcBOS1, BcRAS1, and BcBMP3 were significantly upregulated,whereas BcPLC1, BcBCG1, BcCDC4, BcSAK1, BcATF1, and BcBAP1 were significantly downregulated(P<0.05).BcSDR1 was obviously upregulated in BcBCG2, BcBCG3, BcPKA1, and BcPKAR RNA interference(RNAi) mutants, but significantly downregulated in BcPKA2, BcBMP1, and BcBMP3 RNAi mutants. Thus, BcBCG2, BcBCG3, BcPKA1, and BcPKAR negatively regulate BcSDR1 expression, whereas BcPKA2, BcBMP1, and BcBMP3 positively regulate BcSDR1expression.

Unimolecular artificial transmembrane channel with terminal dihydrogen phosphate groups showing transport selectivity for ammonium

A new artificial transmembrane channel molecule bearing dihydrogen phosphate groups has been synthesized.The terminal dihydrogen phosphate groups enable the channel to be highly negatively charged at both ends of the channel structures.The artificial channel could incorporate into the lipid bilayer efficiently under low concentration.The channel displays high NH4+/K+selectivity due to the electrostatic interaction and hydrogen bonding between NH4+and the terminal dihydrogen phosphate groups.

Responsive Polymers with Contraction-arisen Helicity and Biomimetic Membrane-spanning Transport Functions

Responsive polymers have attracted increasing attention for prospective design of smart materials.The development of multifunctional responsive materials is very dependent on polymeric structures that can be manipulated with the change of microenvironment at the molecular level.Herein,we report a type of responsive coordination polymers(RCPs)consisting of dual phenanthroline-oxadiazole(DPO)units and metal Zn^(2+)ions,which can contract from linear structure into topologically helical structure driven by hydrophobic effect while changing the microenvironment from nonpolar solvent to aqueous media.The symmetry breaking of RCPs was confirmed by circular dichroism(CD)spectra and atomic force microscope(AFM)images,clearly demonstrating the intramolecularly contraction-arisen helicity.Moreover,RCPs can intelligently adapt different microenvironments by changing their conformations,as evidenced by a demonstration of biomimetic lipid bilayer-based vesicle experiments.Furthermore,RCPs show significant concentration-dependent transmembrane transport functions,implying that RCPs are able to span cellular membranes to form channels inside the hydrophobic lipid bilayers.At the same time,the electrophysiological conductance experiments further underpin the biomimetic transport functions and channel-based conduction mechanism of RCPs.This study demonstrates an important paradigm of responsive polymers performing microenvironment-induced conformational change and thereof unique functions,and thus provides valuable insights on the development of functional responsive materials.