1.The plateau zokors' learning and memory ability is related to the high expression levels of foxP2 in the brain.
Ben-Yuan MA ; Lian WEI ; Sheng-Zhen SUN ; Duo-Wei WANG ; Deng-Bang WEI
Acta Physiologica Sinica 2014;66(2):135-144
Plateau zokor (Myospalax baileyi) is a subterranean mammal. Plateau zokor has high learning and memory ability, and can determine the location of blocking obstacles in their tunnels. Forkhead box p2 (FOXP2) is a transcription factor implicated in the neural control of orofacial coordination and sensory-motor integration, particularly with respect to learning, memory and vocalization. To explore the association of foxP2 with the high learning and memory ability of plateau zokor, the cDNA of foxP2 of plateau zokor was sequenced; by using plateau pika as control, the expression levels of foxP2 mRNA and FOXP2 protein in brain of plateau zokor were determined by real-time PCR and Western blot, respectively; and the location of FOXP2 protein in the brain of plateau zokor was determined by immunohistochemistry. The result showed that the cDNA sequence of plateau zokor foxP2 was similar to that of other mammals and the amino acid sequences showed a relatively high degree of conservation, with the exception of two particular amino acid substitutions [a Gln (Q)-to-His (H) change at position 231 and a Ser (S)-to-Ile (I) change at position 235]. Higher expression levels of foxP2 mRNA (3-fold higher) and FOXP2 protein (>2-fold higher) were detected in plateau zokor brain relative to plateau pika brain. In plateau zokor brain, FOXP2 protein was highly expressed in the cerebral cortex, thalamus and the striatum (a basal ganglia brain region). The results suggest that the high learning and memory ability of plateau zokor is related to the high expression levels of foxP2 in the brain.
Amino Acid Sequence
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Amino Acid Substitution
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Animals
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Brain
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metabolism
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Forkhead Transcription Factors
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metabolism
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Lagomorpha
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physiology
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Learning
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Memory
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RNA, Messenger
2.An Ile93Met substitution in the UCH-L1 gene is not a disease-causing mutation for idiopathic Parkinson's disease.
Chinese Medical Journal 2003;116(2):312-313
OBJECTIVETo ascertain whether a coding mutation (Ile93Met) in ubiquitin carboxy-terminal hydrolase (UCH-L1) gene plays a role in idiopathic Parkinson's disease (IPD).
METHODSPolymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP) was used to distinguish the wild-type (two DNA fragments of 34 and 126 bp) from the variant allele (three fragments of 34, 60 and 66 bp) because the mutation created a new site for restriction endonuclease BsmF1. DNA was isolated from various blood samples using a phenolchloroform extraction.
RESULTSIle93Met substitution was found neither in PD patients nor in controls.
CONCLUSIONSOur study suggested that Ile93Met of UCH-L1 gene did not influence risk of IPD.
Aged ; Amino Acid Substitution ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Parkinson Disease ; genetics ; Thiolester Hydrolases ; genetics ; physiology ; Ubiquitin Thiolesterase
3.Extracellular quality control in the epididymis.
Gail A CORNWALL ; H Henning von HORSTEN ; Douglas SWARTZ ; Seethal JOHNSON ; Kim CHAU ; Sandra WHELLY
Asian Journal of Andrology 2007;9(4):500-507
The epididymal lumen represents a unique extracellular environment because of the active sperm maturation process that takes place within its confines. Although much focus has been placed on the interaction of epididymal secretory proteins with spermatozoa in the lumen, very little is known regarding how the complex epididymal milieu as a whole is maintained, including mechanisms to prevent or control proteins that may not stay in their native folded state following secretion. Because some misfolded proteins can form cytotoxic aggregate structures known as amyloid, it is likely that control/surveillance mechanisms exist within the epididymis to protect against this process and allow sperm maturation to occur. To study protein aggregation and to identify extracellular quality control mechanisms in the epididymis, we used the cystatin family of cysteine protease inhibitors, including cystatin-related epididymal spermatogenic and cystatin C as molecular models because both proteins have inherent properties to aggregate and form amyloid. In this chapter, we present a brief summary of protein aggregation by the amyloid pathway based on what is known from other organ systems and describe quality control mechanisms that exist intracellularly to control protein misfolding and aggregation. We then present a summary of our studies of cystatin-related epididymal spermatogenic (CRES) oligomerization within the epididymal lumen, including studies suggesting that transglutaminase cross-linking may be one mechanism of extracellular quality control within the epididymis.
Amino Acid Substitution
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Amyloid
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physiology
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standards
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Cystatin C
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Cystatins
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genetics
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Dimerization
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Epididymis
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physiology
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Humans
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Male
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Mutation
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Protein Folding
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Proteins
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standards
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Quality Control
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Sperm Maturation
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physiology
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Transglutaminases
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physiology
4.Characterization of mitosis-specific phosphorylation of tumor-associated microtubule-associated protein.
Kyung Uk HONG ; Hyun Jun KIM ; Chang Dae BAE ; Joobae PARK
Experimental & Molecular Medicine 2009;41(11):832-840
Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2), has been recently shown to be involved in the assembly and maintenance of mitotic spindle and also plays an essential role in maintaining the fidelity of chromosome segregation during mitosis. We have previously reported that TMAP is phosphorylated at multiple residues specifically during mitosis, and characterized the mechanism and functional importance of phosphorylation at one of the mitosis-specific phosphorylation residues (i.e., Thr-622). However, the phosphorylation events at the remaining mitotic phosphorylation sites of TMAP have not been fully characterized in detail. Here, we report on generation and characterization of phosphorylated Thr-578- and phosphorylated Thr-596-specific antibodies. Using the antibodies, we show that phosphorylation of TMAP at Thr-578 and Thr-596 indeed occurs specifically during mitosis. Immunofluorescent staining using the antibodies shows that these residues become phosphorylated starting at prophase and then become rapidly dephosphorylated soon after initiation of anaphase. Subtle differences in the kinetics of phosphorylation between Thr-578 and Thr-596 imply that they may be under different mechanisms of phosphorylation during mitosis. Unlike the phosphorylation-deficient mutant form for Thr-622, the mutant in which both Thr-578 and Thr-596 had been mutated to alanines did not induce significant delay in progression of mitosis. These results show that the majority of mitosis-specific phosphorylation of TMAP is limited to pre-anaphase stages and suggest that the multiple phosphorylation may not act in concert but serve diverse functions.
Amino Acid Substitution
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Antibodies, Monoclonal/chemistry
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Cytoskeletal Proteins/genetics/*metabolism
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Hela Cells
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Humans
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Kinetics
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Mitosis/*physiology
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Mutation
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Mutation, Missense
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Phosphorylation/physiology
5.Solid-phase synthesis and biological characterization of S12A-HNTX-IV and R29A-HNTX-IV: two mutants of hainantoxin-IV.
Xia XU ; Xia XIONG ; Dong-Ling LI ; Yu-Cheng XIAO ; Xian-Chun WANG ; Song-Ping LIANG
Chinese Journal of Biotechnology 2005;21(1):92-96
Hainantoxin-IV (HNTX-IV) purified from the venom of the spider Selenocosmia hainana is a potent antagonist that acts on tetrodotoxin-sensitive (TrX-S) sodium channels. It is a 35-residue polypeptide and includes three disulfide bridges. In order to investigate the structure-function relationship of HNTX-IV, two mutants (S12A-HNTX-IV and R29A-HNTX-IV) of HNTX-TV in which Ser12 and Arg29 were replaced by Ala respectively, were synthesized by solid-phase Fmoc chemistry, followed by oxidative refolding of purified peptides under the optimal conditions. The synthetic mutants were analyzed by MALDI-TOF mass spectrometry, nuclear magnetic resonance spectroscopy (NMR) and electrophysiological experiments for molecular weight, conformation and physiological activity, respectively. The results show that the mutants and native HNTX-IV (nHNTX-IV) have almost identical three-dimensional structures. The bioactivity level of S12A-HNTX-IV is also about the same as that of nHNTX-IV, suggesting that Ser12 does not play any important role for the bioactivity of this toxin. The bioactivity of R29A-HNTX-IV is reduced by at last 155 times, indicating that Arg29 is a key residue relative to the bioactivity of HNTX-IV. It is presumed that the decrease in activity of R29A-HNTX-IV is due to the changes of the property in the binding site rather than the change in the basic conformation of the molecule.
Amino Acid Substitution
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Animals
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Mutation
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Sodium Channel Blockers
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Sodium Channels
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drug effects
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physiology
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Spider Venoms
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chemical synthesis
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genetics
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Structure-Activity Relationship
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Tetrodotoxin
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pharmacology
6.Cysteine-179 of I kappa B kinase beta plays a critical role in enzyme activation by promoting phosphorylation of activation loop serines.
Mi Sun BYUN ; Jin CHOI ; Dae Myung JUE
Experimental & Molecular Medicine 2006;38(5):546-552
I kappa B kinase beta (IKK beta) subunit of IKK complex is essential for the activation of NF-kappa B in response to various proinflammatory signals. Cys-179 in the activation loop of IKK beta is known to be the target site for IKK inhibitors such as cyclopentenone prostaglandins, arsenite, and antirheumatic gold compounds. Here we show that a mutant IKK beta in which Cys-179 is substituted with alanine had decreased activity when it was expressed in HEK-293 cells, and TNF stimulation did not restore the activity. Phosphorylation of activation loop serines (Ser-177 and Ser-181) which is required for IKK beta activation was reduced in the IKK beta (C179A) mutant. The activity of IKK beta (C179A) was partially recovered when its phosphorylation was enforced by coexpression with mitogen-activated protein kinase kinase kinases (MAPKKK) such as NF-kappa B inducing kinase (NIK) and MAPK/extracellular signal-regulated kinase kinase kinase 1(MEKK1) or when the serine residues were replaced with phospho-mimetic glutamate. The IKK beta (C179A) mutant was normal in dimer formation, while its activity abnormally responded to the change in the concentration of substrate ATP in reaction mixture. Our results suggest that Cys-179 of IKK beta plays a critical role in enzyme activation by promoting phosphorylation of activation-loop serines and interaction with ATP.
Transfection
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Serine/*metabolism
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Protein Binding
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Phosphorylation
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Mutant Proteins/chemistry
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MAP Kinase Kinase Kinases/metabolism
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I-kappa B Kinase/*chemistry
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Humans
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Hela Cells
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Enzyme Activation/*physiology
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Cysteine/*physiology
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Cells, Cultured
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Catalytic Domain
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Amino Acid Substitution/physiology
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Adenosine Triphosphate/metabolism
7.Energy-coupling mechanism of the multidrug resistance transporter AcrB: Evidence for membrane potential-driving hypothesis through mutagenic analysis.
Protein & Cell 2017;8(8):623-627
Amino Acid Substitution
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Drug Resistance, Multiple, Bacterial
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physiology
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Escherichia coli
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physiology
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Escherichia coli Proteins
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genetics
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metabolism
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Membrane Potentials
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physiology
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Models, Biological
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Multidrug Resistance-Associated Proteins
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genetics
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metabolism
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Mutation, Missense
8.Lack of association of COMT Val158Met polymorphism with attention and executive function in patients with schizophrenia.
Qiang WANG ; Zhenxing YANG ; Linhui LIANG ; Xiaochu GU ; Chaohua HUANG ; Mingli LI ; Wei DENG ; Xiaohong MA ; Yingcheng WANG ; Liansheng ZHAO ; Bo XIANG ; Tao LI
Chinese Journal of Medical Genetics 2014;31(5):650-653
OBJECTIVETo explore the association of a functional polymorphism Val158Met of COMT gene and attention and executive function in first-episode treatment-naive patients with schizophrenia and healthy controls.
METHODSTrail making test (TMT) and clinical performances were evaluated in 103 first-episode treatment-naive patients with schizophrenia and 99 healthy controls. Polymorphism of COMT Val158Met was analyzed using polymerase chain reaction-restriction fragment length polymorphism method. A general linear model was used to investigate the effect of genotype subgroups on the attention and executive function.
RESULTSThere was a significant difference between control subjects and patients with schizophrenia on the TMT-A and B. However, no significant difference among Val/Val, Val/Met and Met/Met on the TMT-A and B in control subjects and patients with schizophrenia was detected.
CONCLUSIONThe association among COMT Met variant and trail making testing (attention and executive function) has been replicated. However, no association of COMT Met variant with disruption of dopaminergic influence on neurocognitive function was detected. This may be due to the heterogeneity of population.
Adolescent ; Adult ; Amino Acid Substitution ; Attention ; physiology ; Catechol O-Methyltransferase ; genetics ; Executive Function ; physiology ; Female ; Gene Frequency ; Genotype ; Humans ; Male ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Restriction Fragment Length ; Schizophrenia ; genetics ; physiopathology ; Schizophrenic Psychology ; Trail Making Test ; Young Adult
9.The association of Pro12Ala polymorphism of peroxisome proliferator-activated receptor-gamma gene with serum osteoprotegerin levels in healthy Korean women.
Eun Jung RHEE ; Ki Won OH ; Eun Joo YUN ; Chan Hee JUNG ; Cheol Young PARK ; Won Young LEE ; Eun Sook OH ; Ki Hyun BAEK ; Moo Il KANG ; Sung Woo PARK ; Sun Woo KIM
Experimental & Molecular Medicine 2007;39(6):696-704
Recent evidences suggest that the activation of peroxisome proliferator-activated receptor (PPAR)-gamma, which is an important transcriptional factor in adipocyte differentiation, also plays an important role in the bone microenvironment. The objective of the study was to clarify whether Pro12Ala polymorphism was related to the serum OPG levels and bone mineral metabolism in healthy Korean women. In 239 Korean women (mean age 51 years), who participated in medical check-up program in a health promotion center, anthropometric measurements, lumbar spine and femoral neck bone mineral density (BMD), bone turnover markers, such as serum total alkaline phosphatase (ALP) levels, urine deoxypyridinoline levels, and 24-h urine calcium excretion were measured. Serum levels of OPG were measured with ELISA method. DNAs were extracted from the samples and the genotyping of the Pro12Ala polymorphism (rs1801282) in the PPAR-gamma gene was performed via an allelic discrimination assay using a TaqMan probe. In addition, we examined the haplotype analysis between two polymorphisms of PPAR-gamma gene, Pro12Ala in exon B and C161T in exon 6 (rs3856806). Allelic frequencies were 0.950 for Pro allele and 0.050 for Ala allele, which was in compliance with Hardy- Weinberg equilibrium, and there was no Ala12Ala genotype among the genotyped subjects. Mean serum OPG level was significantly lower (P=0.035), and serum total ALP was significantly higher (P=0.014) in the Pro12Ala genotype group compared with the Pro12Pro genotype group, which were consistently significant even after adjustment for weight, height, and serum follicle stimulating hormone (FSH). In multiple regression analysis with serum OPG as the dependent variable and age, weight, ALP, femoral neck BMD and Pro12Ala genotype included in the model, only Pro12Ala genotype was significant determinant of serum OPG level (beta=-0.136, P=0.035). The haplotype analysis with C161T polymorphism revealed that subjects with Ala and T alleles showed significantly lower serum OPG levels compared with those with Pro12Pro/CC genotype, which were consistently significant even after adjustment for age, weight, height and FSH (P=0.010). This result suggests statistically significant association of Pro12Ala polymorphisms with serum OPG levels in Korean females.
Alanine/genetics
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*Amino Acid Substitution
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Asian Continental Ancestry Group
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Bone Density/physiology
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Bone and Bones/*metabolism
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Enzyme-Linked Immunosorbent Assay
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Female
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Gene Frequency
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Humans
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Korea
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Middle Aged
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*Mutation
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Osteoprotegerin/*blood/metabolism
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PPAR gamma/*genetics/metabolism
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Polymorphism, Genetic
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Proline/genetics
10.Advances in the study of molecular mechanism of APOBEC3G anti-HIV-1.
Bo FAN ; Shan CEN ; Jian-dong JIANG
Acta Pharmaceutica Sinica 2008;43(7):678-682
Apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3 protein G (APOBEC3G) is part of the innate immune system of host cells and has cytidine deaminase activity. It specifically incorporates into the virion during HIV-1 replication. The incorporation of APOBEC3G needs its interaction with HIV-1 Gag. In the HIV-1 reverse transcription process, APOBEC3G deaminates dC to dU in the first minus strand cDNA, and then induces extensive hypermutation in the viral genome. Besides deamination, APOBEC3G also inhibits HIV-1 by some kinds of non-deamination mechanisms which need to be further elucidated. HIV-1 Vif counteracts the activity of APOBEC3G by an ubiquitin-proteasome-mediated degradation of APOBEC3G. As a broad spectrum inhibitor of viruses, APOBEC3G also inhibits various retroviruses, retrotransposons and other viruses like HBV. Upregulating the expression of APOBEC3G or blocking the Vif-mediated degradation of APOBEC3G might be novel strategies to treat HIV-1 infection in the future.
APOBEC-3G Deaminase
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Amino Acid Substitution
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Anti-HIV Agents
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metabolism
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Cytidine Deaminase
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genetics
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metabolism
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Gene Expression
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HIV Infections
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metabolism
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HIV-1
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genetics
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physiology
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Humans
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Virus Replication
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vif Gene Products, Human Immunodeficiency Virus
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genetics
;
metabolism