Absence of association between SNPs in the promoter region of the insulin-like growth factor 1 (IGF-1) gene and longevity in the Han Chinese population

Previous studies have indicated that genetic variations in the factors of insulin/insulin-like growth factor 1 (IGF-1) signaling pathway could influence human life-span by affecting IGF-1 levels. The promoter region of the IGF-1 gene is an obvious candida

A Profound Role for the Expansion of Trypsin-Like Serine Protease Family in the Evolution of Hematophagy in Mosquito

The trypsin-like serine protease (Tryp_SPc) family is ubiquitous in animals and plays diverse roles, especially in the digestive system, in different phyla. In the mosquito, some Tryp_SPc proteases make important contributions to the digestion of the bloo

A molecular model of braid-like DNA structure

The three-dimensional molecular models of DNA triple helices and triple-stranded brain-like structure were built up by molecular architecture, and their structural features and energy decomposition were examined. The results showed: (i) The base triplet is the element forming braid-like and triple helix DNA; (ii) Under specified conditions, DNA could form the triplet-stranded braid-like structure; (iii) DNA stability of the braid-like structure is less than that of the triple helix structure. (C) 1995 Academic Press Limited.

Enriched environment experience overcomes the memory deficits and depressive-like behavior induced by early life stress

Stress in early life is believed to cause cognitive and affective disorders, and to disrupt hippocampal synaptic plasticity in adolescence into adult, but it is unclear whether exposure to enriched environment (EE) can overcome these effects. Here, we rep

Nuclear matrix of the most primitive eukaryote Archezoa

Accumulating evidence suggests that unicellular Archezoa are the most primitive eukaryotes and their nuclei are of significance to the study of evolution of the eukaryotic nucleus. Nuclear matrix is an ubiquitous important structure of eukaryotic nucleus; its evolution is certainly one of the most important parts of the evolution of nucleus. To study the evolution of nuclear matrix, nuclear matrices of Archezoa are investigated. Giardia lamblia cells are extracted sequentially. Both embedment-free section EM and whole mount cell EM of the extracted cells show that, like higher eukaryotes, this species has a residual nuclear matrix in its nucleus and rich intermediate filaments in its cytoplasm, and the two networks connect with each other to form a united network. But its nuclear matrix does not have nucleolar matrix and its lamina is not as typical as that of higher eukaryotes; Western blotting shows that lamina of Giardia and two other Archezoa Entamoeba invadens and Trichomonas vaginali all contain only one polypeptide each which reacts with a mammalia anti-lamin polyclonal serum and is similar to lamin B (67 ku) of mammlia in molecular weight. According to the results and references, it is suggested that nuclear matrix is an early acquisition of the eukaryotic nucleus, and it and the "eukaryotic chromatin" as a whole must have originated very early in the process of evolution of eukaryotic cell, and their origin should be an important prerequisite of the origin of eukaryotic nucleus; in the iamin (gene) family, B-type lamins (gene) should be the ancestral type and that A-type lamins (gene) might derive therefrom.

Theoretical studies on conformation comparison of braid-like and triplex DNA

Based on the experimental data of scanning tunneling microscopy (STM), models of three-stranded braid-like DNAs composed by three kinds of base triplets AAA, TAT and GCA were constructed. We investigated the braid-like DNAs and their comparative tripler DNAs using a molecular mechanics method. The three strands of braid-like DNAs are proven equivalent, while those of tripler DNAs are not. The conformational energies for braid-like DNAs were found to be higher than that for tripler DNAs. Each period in one strand of braid-like DNA has 18 nucleotides, half of which are right-handed, while the other half are left-handed. Additional discussions concerning sugar puckering modes and the H-bonds are also included. (C) 1999 Elsevier Science B.V. All rights reserved.

Pituitary adenylate cyclase-activating polypeptide

Pituitary adenylate cyclase-activating polypeptide (PACAP) which belongs to the secretin/glucagon/ VIP family has been originally isolated from the sheep hypothalamus on the basis of its ability to stimulate cAMP formation in culture rat anterior pituitary cells. Post-translational processing of the PACAP precursor generates two biologically active molecular forms, PACAP-38 and PACAP-27. The primary structure of PACAP has been remarkably conserved during evolution. The sequence of PACAP-27 exhibits substantial similarities with those of vasoactive intestinal polypeptide (VIP), glucagon and secretin. The gene encoding the PACAP precursor is widely expressed in brain and various peripheral organs, notably in endocrine glands, gastro-intestinal, urogenital tracts and respiratory system. In vivo, and in vitro studies have shown that PACAP exhibits multiple activities especially a trophic activity during ontogenesis, notably in the adrenal medulla and the central nervous system. The biological effects of PACAP are mediated through three distinct receptor subtypes which exhibit differential affinities for PACAP and VIP. The PAC1 receptor, which shows high selectivity for PACAP, is coupled to several transduction systems. In contrast, VPAC1 and VPAC2, which bind with the same affinity for PACAP and VIP, are mainly coupled to the adenylyl cyclase pathway. In conclusion, PACAP is neuropeptide, and it functions as a hypothalamic hormone, neurohormone, neuromodulator, vasodilator, neurotransmitter or trophic factor in the brain and the various organs.

鲫鱼蛋白激酶PKR-like的Zα结构域与聚肌胞苷酸的结合

根据鲫鱼类PKR蛋白激酶基因(CaPKR-like)的全长cDNA序列,克隆CaPKR-likeZα结构域cDNA(Zα1、Zα2和Zα1Zα2),原核表达成功获得3种融合蛋白PZα1、PZα2和PZα1Zα2。凝胶阻滞实验结果显示:PZα1、PZα2、PZα1和PZα2混合表达蛋白不能与聚肌胞苷酸(PolyI∶C)结合,而表达完整的Zα结构域的PZα1Zα2与PolyI∶C有明显的结合现象。另外,3种表达多肽PZα1、PZα2和PZα1Zα2在体外分别都能聚合形成二聚体。与PZα1相比,PZα2和PZα

DnaJ-like protein gene sll1384 is involved in phototaxis in Synechocystis sp PCC 6803

In Synechocystis sp. PCC 6803, gene sll1384 encodes a protein with a DnaJ domain at its N-terminal portion and a TPR domain at the C-terminal portion. An sll1384 mutant shows no difference from the wild type in adaptation to different temperatures, but almost completely loses its capability of phototactic movement. After complementation with sll1384, the mutant regains the phototaxis. As shown with electron microscopy, on the cell surface, mutant cells have pili that appear to be the same as that of the wild type. Also, the transformation efficiency remains unchanged in the mutant. It is postulated that Sll1384 regulates phototaxis of Synechocystis through protein-protein interaction. It is the first DnaJ-like protein gene identified in a cyanobacterium for a role in phototaxis.

Enhanced grass carp reovirus resistance of Mx-transgenic rare minnow (Gobiocypris rarus)

In the interferon-induced antiviral mechanisms, the Mx pathway is one of the most powerful. Mx proteins have direct antiviral activity and inhibit a wide range of viruses by blocking an early stage of the viral genome replication cycle. However, antiviral activity of piscine Mx remains unclear in vivo. In the present study, an Mx-like gene was cloned, characterized and gene-transferred in rare minnow Gobiocypris rarus, and its antiviral activity was confirmed in vivo. The full length of the rare minnow Mx-like cDNA is 2241 bp in length and encodes a polypeptide of 625 amino acids with an estimated molecular mass of 70.928 kDa and a predicted isoelectric point of 7.33. Analysis of the deduced amino acid sequence indicated that the mature peptide contains an amino-terminal tripartite GTP-binding motif, a dynamin family signature sequence, a GTPase effector domain and two carboxy-terminal leucine zipper motifs, and is the most similar to the crucian carp (Carassius auratus) Mx3 sequence with an identity of 89%. Both P0 and F1 generations of Mx-transgenic rare minnow demonstrated very significantly high survival rate to GCRV infection (P < 0.01). The mRNA expression of Mx gene was consistent with survival rate in F1 generation. The virus yield was also concurrent with survival time using electron microscope technology. Rare minnow has Mx gene(s) of its own but introducing more Mx gene improves their resistance to GCRV. Mx-transgenic rare minnow might contribute to control the GCRV diseases. (C) 2008 Published by Elsevier Ltd.

Origin and evolution of the RIG-I like RNA helicase gene family

Background: The DExD/H domain containing RNA helicases such as retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5) are key cytosolic pattern recognition receptors (PRRs) for detecting nucleotide pathogen associated molecular patterns (PAMPs) of invading viruses. The RIG-I and MDA5 proteins differentially recognise conserved PAMPs in double stranded or single stranded viral RNA molecules, leading to activation of the interferon system in vertebrates. They share three core protein domains including a RNA helicase domain near the C terminus (HELICc), one or more caspase activation and recruitment domains (CARDs) and an ATP dependent DExD/H domain. The RIG-I/MDA5 directed interferon response is negatively regulated by laboratory of genetics and physiology 2 (LGP2) and is believed to be controlled by the mitochondria antiviral signalling protein (MAVS), a CARD containing protein associated with mitochondria. Results: The DExD/H containing RNA helicases including RIG-I, MDA5 and LGP2 were analysed in silico in a wide spectrum of invertebrate and vertebrate genomes. The gene synteny of MDA5 and LGP2 is well conserved among vertebrates whilst conservation of the gene synteny of RIG-I is less apparent. Invertebrate homologues had a closer phylogenetic relationship with the vertebrate RIG-Is than the MDA5/LGP2 molecules, suggesting the RIG-I homologues may have emerged earlier in evolution, possibly prior to the appearance of vertebrates. Our data suggest that the RIG-I like helicases possibly originated from three distinct genes coding for the core domains including the HELICc, CARD and ATP dependent DExD/H domains through gene fusion and gene/domain duplication. Furthermore, presence of domains similar to a prokaryotic DNA restriction enzyme III domain (Res III), and a zinc finger domain of transcription factor (TF) IIS have been detected by bioinformatic analysis. Conclusion: The RIG-I/MDA5 viral surveillance system is conserved in vertebrates. The RIG-I like helicase family appears to have evolved from a common ancestor that originated from genes encoding different core functional domains. Diversification of core functional domains might be fundamental to their functional divergence in terms of recognition of different viral PAMPs.

Staphylococcus aureus lipoproteins trigger human corneal epithelial innate response through toll-like receptor-2

Bacterial lipoproteins (LP) are a family of cell wall components found in a wide variety of bacteria. In this study, we characterized the response of HUCL, a telomerase-immortalized human corneal epithelial cell (HCEC) line, to LP isolated from Staphylococcus (S) aureus. S. aureus LP (saLP) prepared by Triton X-114 extraction stimulated the activation of NF-kappa B, JNK, and P38 signaling pathways in HUCL cells. The extracts failed to stimulate NF-kappa B activation in HUCL cells after lipoprotein lipase treatment and in cell lines expressing TLR4 or TLR9, but not TLR2, indicating lipoprotein nature of the extracts. saLP induced the up-regulation of a variety of inflammatory cytokines and chemokines (IL-6, IL-8, ICAM-1). antimicrobial molecules (hBD-2, LL-37, and iNOS), and homeostasis genes (Mn-SOD) at both the mRNA level and protein level. Similar inflammatory response to saLP was also observed in primarily cultured HCECs using the production of IL-6 as readout. Moreover, TLR2 neutralizing antibody blocked the saLP-induced secretion of IL-6, IL-8 and hBD2 in HUCL cells. Our findings suggest that saLP activates TLR2 and triggers innate immune response in the cornea to S. aureus infection via production of proinflammatory cytokines and defense molecules. (C) 2007 Elsevier Ltd. All rights reserved.

RNAi suppression of zebrafish peptidoglycan recognition protein 6 (zfPGRP6) mediated differentially expressed genes involved in Toll-like receptor signaling pathway and caused increased susceptibility to Flavobacterium columnare

In Drosophila, Toll signaling cascade, which resembles the mammalian Toll-like receptor (TLR)/IL-1R signaling pathways and regulates the expression of anti-microbial peptide genes, mainly relies on peptidoglycan recognition proteins (PGRPs) for the detection of bacterial pathogens. To explore the effect of zebrafish peptidoglycan recognition protein 6 (zfPGRP6) on Toll-like receptor signaling pathway, RNA interference (siRNA) and real time quantitative PCR (RQ-PCR) methods were used to identify differentially expressed genes regulated by zfPGRP6. The target genes included TLR2, TLR3, TLR5, TLR7, TLR8, IL1R, Sterile-alpha and Armadillo motif containing protein (SARM), myeloid differentiation factor 88 (MyD88) and nuclear factor (NF)-kappa B2 (p100/p52). The results of RQ-PCR showed that RNAi-mediated Suppression of zfPGRP6 significantly down-regulated the expression of TLR2, TLR5, IL1R, SARM, MyD88 and p100/p52. The expression of beta-defensin-1 was also down-regulated in those embryos silenced by zfPGRP6. In challenge experiments to determine the anti-bacterial response to Gram-negative bacteria, RNAi knock-down of zfPGRP6 markedly increased susceptibility to Flavobacterium columnare. (C) 2008 Elsevier B.V. All rights reserved.

C1q-like inhibits p53-mediated apoptosis and controls normal hernatopoiesis during zebrafish embryogenesis

Except for the complement C1q, the immunological functions of other C1q family members have remained unclear. Here we describe zebrafish C1q-like, whose transcription and translation display a uniform distribution in early embryos, and are restricted to mid-hind brain and eye in later embryos. In vitro studies showed that C1q-like could inhibit the apoptosis induced by ActD and CHX in EPC cells, through repressing caspase 3/9 activities. Moreover, its physiological roles were studied by morpholino-mediated knockdown in zebrafish embryogenesis. In comparison with control embryos, the C1q-like knockdown embryos display obvious defects in the head and cramofacial development mediated through p53-induced apoptosis, which was confirmed by the in vitro transcribed C1q-like mRNA or p53 MO co-injection. TUNEL assays revealed extensive cell death, and caspase 3/9 activity measurement also revealed about two folds increase in C1q-like morphant embryos, which was inhibited by p53 MO co-injection. Real-time quantitative PCR showed the up-regulation expression of several apoptosis regulators such as p53, mdm2, p21, Box and caspase 3, and down-regulation expression of hbae1 in the C1q-like morphant embryos. Knockdown of C1q-like in zebrafish embryos decreased hemoglobin production and impaired the organization of mesencephalic vein and other brain blood vessels. Interestingly, exposure of zebrafish embryos to UV resulted in an increase in mRNA expression of C1q-like, whereas over-expression of C1q-like was not enough resist to the damage. Furthermore, C1q-like transcription was up-regulated in response to pathogen Aeromonas hydrophila, and embryo survival significantly decreased in the C1q-like morphants after exposure to the bacteria. The data suggested that C1q-like might play an antiapoptotic and protective role in inhibiting p53-dependent and caspase 3/9-mediated apoptosis during embryogenesis, especially in the brain development, and C1q-like should be a novel regulator of cell survival during zebrafish embryogenesis. (c) 2008 Elsevier Inc. All rights reserved.

Molecular cloning, characterization and expression analysis of the PKZ gene in rare minnow Gobiocypris rarus

Double-stranded RNA-activated protein kinase (PKR) plays an important rote in interferon-induced antiviral responses, and is also involved in intracellular signaling pathways, including the apoptosis, proliferation, and transcription pathways. In the present study, a PKR-like gene was cloned and characterized from rare minnow Gobiocypris rarus. The full length of the rare minnow PKR-like (GrPKZ) cDNA is 1946 bp in Length and encodes a polypeptide of 503 amino acids with an estimated molecular mass of 57,355 Da and a predicted isoelectric point of 5.83. Analysis of the deduced amino acid sequence indicated that the mature peptide contains two Zalpha domains and one S_TKc domain, and is most similar to the crucian carp (Carassius auratus) PKR-like amino acid sequence with an identity of 77%. Quantitative RT-PCR analysis showed that GrPKZ mRNA expression is at low levels in gill, heart, intestine, kidney, liver, muscle and spleen tissues in healthy animals and up-regulated by viruses and bacteria. After being infected by grass carp reovirus, GrPKZ expression was up-regulated from 24 h post-injection and lasted until the fish became moribund (P < 0.05). Following infection with Aeromonas hydrophila, GrPKZ transcripts were induced at 24 h post-injection (P < 0.05) and returned to control levels at 120 h post-injection. These data imply that GrPKZ is involved in antiviral defense and Toll-like receptor 4 signaling pathway in bacterial infection. (C) 2008 Elsevier Ltd. All rights reserved.