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The Journal of Biological Chemistry Sep 2013Large lipid transfer proteins are involved in lipid transportation and diverse other molecular processes. These serum proteins include vitellogenins, which are egg yolk...
Large lipid transfer proteins are involved in lipid transportation and diverse other molecular processes. These serum proteins include vitellogenins, which are egg yolk precursors and pathogen pattern recognition receptors, and apolipoprotein B, which is an anti-inflammatory cholesterol carrier. In the honey bee, vitellogenin acts as an antioxidant, and elevated vitellogenin titer is linked to prolonged life span in this animal. Here, we show that vitellogenin has cell and membrane binding activity and that it binds preferentially to dead and damaged cells. Vitellogenin binds directly to phosphatidylcholine liposomes and with higher affinity to liposomes containing phosphatidylserine, a lipid of the inner leaflet of cell membranes that is exposed in damaged cells. Vitellogenin binding to live cells, furthermore, improves cell oxidative stress tolerance. This study can shed more light on why large lipid transfer proteins have a well conserved α-helical domain, because we locate the lipid bilayer-binding ability of vitellogenin largely to this region. We suggest that recognition of cell damage and oxidation shield properties are two mechanisms that allow vitellogenin to extend honey bee life span.
Topics: Amino Acid Sequence; Animals; Antioxidants; Bees; Cell Death; Cell Membrane; Cell Separation; Flow Cytometry; Lipid Bilayers; Liposomes; Models, Molecular; Molecular Sequence Data; Oxidative Stress; Phylogeny; Protein Structure, Secondary; Reactive Oxygen Species; Sf9 Cells; Vitellogenins
PubMed: 23897804
DOI: 10.1074/jbc.M113.465021 -
Insect Molecular Biology Dec 2022The protein vitellogenin (Vg) plays a central role in lipid transportation in most egg-laying animals. High Vg levels correlate with stress resistance and lifespan...
The protein vitellogenin (Vg) plays a central role in lipid transportation in most egg-laying animals. High Vg levels correlate with stress resistance and lifespan potential in honey bees (Apis mellifera). Vg is the primary circulating zinc-carrying protein in honey bees. Zinc is an essential metal ion in numerous biological processes, including the function and structure of many proteins. Measurements of Zn suggest a variable number of ions per Vg molecule in different animal species, but the molecular implications of zinc-binding by this protein are not well-understood. We used inductively coupled plasma mass spectrometry to determine that, on average, each honey bee Vg molecule binds 3 Zn -ions. Our full-length protein structure and sequence analysis revealed seven potential zinc-binding sites. These are located in the β-barrel and α-helical subdomains of the N-terminal domain, the lipid binding site, and the cysteine-rich C-terminal region of unknown function. Interestingly, two potential zinc-binding sites in the β-barrel can support a proposed role for this structure in DNA-binding. Overall, our findings suggest that honey bee Vg bind zinc at several functional regions, indicating that Zn -ions are important for many of the activities of this protein. In addition to being potentially relevant for other egg-laying species, these insights provide a platform for studies of metal ions in bee health, which is of global interest due to recent declines in pollinator numbers.
Topics: Bees; Animals; Vitellogenins; Insect Proteins; Zinc; Binding Sites; Lipids
PubMed: 36054587
DOI: 10.1111/imb.12807 -
Zoological Science Apr 2014Vitellogenesis has been extensively studied in oviparous vertebrates, including teleost fishes, while not much is known with regard to jawless hagfishes, modern...
Vitellogenesis has been extensively studied in oviparous vertebrates, including teleost fishes, while not much is known with regard to jawless hagfishes, modern representatives of the most primitive vertebrate class. This study aimed to characterize vitellogenin (Vtg) and yolk protein (YP) in the inshore hagfish (Eptatretus burgeri) as an initial step to understand vitellogenesis in this species. A putative Vtg fraction was purified from the serum of female hagfish by combinations of hydroxylapatite and ion-exchange chromatography, followed by gel filtration. The purified fraction appeared to contain two distinct Vtgs (Vtg1 and Vtg2) and exhibited biochemical properties resembling those previously reported for teleost Vtgs; these appeared to be female-specific serum proteins and high-molecular-weight proteins in gel filtration (˜505 kDa as the mixture fraction of both Vtgs) and in SDS-PAGE (Vtg1 and Vtg2; ˜210 kDa and ˜195 kDa, respectively). A major YP was also purified from hagfish eggs by combinations of hydroxylapatite chromatography and gel filtration; the apparent native mass of the purified YP was unusually large (> 669 kDa). The purified YP consisted of four polypeptides in SDS-PAGE; the peptide pattern indicated that it consisted of two lipovitellins (Lv1 and Lv2) giving rise to two sets of heavy chains (˜116 kDa and ˜106 kDa, respectively) and two light chains (˜32 kDa and ˜28 kDa, respectively). Additional immunological analysis, Nterminal amino acid sequencing and cDNA cloning firmly confirmed the precursor-product relationship between hagfish Vtgs and Lvs.
Topics: Animals; Egg Proteins; Gene Expression Regulation; Hagfishes; Immunochemistry; Vitellogenins
PubMed: 24694228
DOI: 10.2108/zs130234 -
Proceedings of the National Academy of... Sep 2021Vitellogenin receptor (VgR) plays a pivotal role in ovarian vitellogenin (Vg) uptake and vertical transmission of pathogenic microbes and symbionts. However, the...
Vitellogenin receptor (VgR) plays a pivotal role in ovarian vitellogenin (Vg) uptake and vertical transmission of pathogenic microbes and symbionts. However, the regulatory mechanisms of VgR action as an endocytic receptor and translocation from oocyte cytoplasm to the membrane remain poorly understood. Here, by using the migratory locust as a model system, we report that juvenile hormone (JH) promotes VgR phosphorylation at Ser in the second EGF-precursor homology domain. A signaling cascade including GPCR, PLC, extracellular calcium, and PKC-ι is involved in JH-stimulated VgR phosphorylation. This posttranslational regulation is a prerequisite for VgR binding to Vg on the external surface of the oocyte membrane and subsequent VgR/Vg endocytosis. Acidification, a condition in endosomes, induces VgR dephosphorylation along with the dissociation of Vg from VgR. Phosphorylation modification is also required for VgR recycling from oocyte cytoplasm to the membrane. Additionally, VgR phosphorylation and its requirement for Vg uptake and VgR recycling are evolutionarily conserved in other representative insects including the cockroach and the cotton bollworm This study fills an important knowledge gap of low-density lipoprotein receptors in posttranslational regulation, endocytosis, and intracellular recycling.
Topics: Animals; Egg Proteins; Endocytosis; Female; Isoenzymes; Juvenile Hormones; Locusta migratoria; Oocytes; Phosphorylation; Protein Kinase C; Receptors, Cell Surface; Receptors, G-Protein-Coupled; Type C Phospholipases; Vitellogenesis; Vitellogenins
PubMed: 34493670
DOI: 10.1073/pnas.2106908118 -
The Journal of Biological Chemistry 2021The classical role of Vitellogenin (Vg) is providing energy reserves for developing embryos, but its roles appear to extend beyond this nutritional function, and its...
The classical role of Vitellogenin (Vg) is providing energy reserves for developing embryos, but its roles appear to extend beyond this nutritional function, and its importance in host immune defense is garnering increasing research attention. However, Vg-regulated immunological functions are dependent on three different domains within different species and remain poorly understood. In the present study, we confirmed three conserved VG domains-LPD_N, DUF1943, and VWD-in the Chinese mitten crab (Eriocheir sinensis), highlighting functional similarities of Vg in vertebrates and invertebrates. Of these three domains, DUF1943 and VWD showed definitive bacterial binding activity via interaction with the signature components on microbial surfaces, but this activity was not exhibited by the LPD_N domain. Antibacterial assays indicated that only the VWD domain inhibits bacterial proliferation, and this function may be conserved between different species due to the conserved amino acid residues. To further explore the relationship between Vg and polymeric immunoglobulin receptor (pIgR), we expressed EspIgR and the three E. sinensis Vg (EsVg) domains in HEK293T cells, and coimmunoprecipitation assay demonstrated that only the DUF1943 domain interacts with EspIgR. Subsequent experiments demonstrated that EsVg regulates hemocyte phagocytosis by binding with EspIgR through the DUF1943 domain, thus promoting bacterial clearance and protecting the host from bacterial infection. To the best of our knowledge, our work is the first to report distinct domains in Vg inducing different immunological outcomes in invertebrates, providing new evidence that pIgR acts as a phagocytic receptor for Vg.
Topics: Amino Acid Sequence; Animals; Bacteria; Bacterial Adhesion; Base Sequence; Crustacea; HEK293 Cells; Hemocytes; Humans; Phagocytosis; Phylogeny; Protein Domains; Vitellogenins
PubMed: 33177064
DOI: 10.1074/jbc.RA120.015686 -
MBio Feb 2021Many insects are intimately associated with microbial symbionts, which are passed to developing oocytes in the maternal body for ensuring vertical transmission to the...
Many insects are intimately associated with microbial symbionts, which are passed to developing oocytes in the maternal body for ensuring vertical transmission to the next generation. Previous studies uncovered that some symbionts utilize preexisting host's molecular and cellular machineries for targeting oocytes. For example, the major yolk protein vitellogenin (Vg) is massively produced in fat body cells, processed and transported to ovaries, and incorporated into developing oocytes via Vg receptor (VgR)-mediated endocytosis, and some symbiotic bacteria were reported to interact with Vg and migrate to oocytes by hitchhiking the VgR-mediated endocytotic mechanism. In a recent study, Mao et al. (mBio 12:e01142-20, 2020, https://doi.org/10.1128/mBio.01142-20) reported that, in some leafhoppers, a considerable proportion of Vg is incorporated into symbiotic bacteria and translocated into oocytes by hitchhiking the symbiont's vertical transmission mechanism, uncovering the host's cooption of the symbiont's oocyte-targeting machineries and highlighting complicated trajectories toward host-symbiont coevolution and integration.
Topics: Animals; Bacteria; Egg Proteins; Oocytes; Symbiosis; Vitellogenins
PubMed: 33563820
DOI: 10.1128/mBio.02997-20 -
Frontiers in Endocrinology 2021This review summarizes the bulk of evidence about the effect of glyphosate, both technical and formulated, on the ovarian maturation of female crabs, as well as the... (Review)
Review
This review summarizes the bulk of evidence about the effect of glyphosate, both technical and formulated, on the ovarian maturation of female crabs, as well as the effects of glyphosate on sperm production in males of the same species. After long-term assays, made during the 3-month pre-reproductive period of this species, both formulated and technical glyphosate were able to produce a significant incidence of oocyte reabsorption in the ovary, together with a concomitant decreased of vitellogenin content, at concentrations ranging from 0.2 to 1 mg/L. Despite this, after 32-day assays, glyphosate stimulated oocyte growth, in terms of a higher percentage of vitellogenic oocytes, suggesting that glyphosate could be acting as an endocrine disruptor. assays made with isolated ovarian pieces showed a decrease of vitellogenin content, in correlation with lower protein synthesis, although some advance in maturation was observed in the histological analysis. In male crabs exposed to both technical and formulated glyphosate at 1 mg/L, several reproductive imbalances were noted, such as a significant decrease of the sperm count, abnormal spermatophores, and possible disrupting effects of glyphosate on the androgenic gland.
Topics: Androgens; Animals; Brachyura; Dose-Response Relationship, Drug; Endocrine Disruptors; Female; Glycine; Herbicides; Male; Models, Animal; Oocytes; Ovary; Reproduction; Spermatozoa; Vitellogenins; Water Pollutants, Chemical; Glyphosate
PubMed: 33841335
DOI: 10.3389/fendo.2021.643168 -
Parasites & Vectors Dec 2022Mosquito-borne diseases threaten human health, but mosquito control faces various challenges, such as resistance to chemical insecticides. Thus, there is an urgent need...
BACKGROUND
Mosquito-borne diseases threaten human health, but mosquito control faces various challenges, such as resistance to chemical insecticides. Thus, there is an urgent need for more effective and environment-friendly control agents. Capsaicin can downregulate the mTOR signaling pathway of tumor cells. The TOR signaling pathway can mediate the expression of vitellogenin (Vg) to regulate the fecundity of insects. Whether capsaicin has the potential to inhibit fecundity of mosquitoes by regulating TOR pathway and Vg expression is currently unclear.
METHODS
Anopheles stephensi were fed with blood of mice administered capsaicin by gavage or sugar containing capsaicin followed by a blood feeding with normal mice. Then, the engorged female mosquitoes were tubed individually and underwent oviposition. The eggs and individuals in the subsequent development stages, including larvae, pupae, and emerging adults, were counted and compared between the capsaicin treatment and control groups. Additionally, total RNA and protein were extracted from the engorged mosquitoes at 24 h post blood feeding. Real-time PCR and western blot were performed to detect the transcriptional level and protein expression of the key fecundity-related molecules of mosquitoes. Finally, TOR signaling pathway was inhibited via rapamycin treatment, and changes in fecundity and the key molecule transcription and protein expression levels were examined to verify the role of TOR signaling pathway in the effect of capsaicin on mosquito fecundity.
RESULTS
The laid and total eggs (laid eggs plus retained eggs) of An. stephensi were significantly reduced by feeding on the blood of capsaicin-treated mice (P < 0.01) or capsaicin-containing sugar (P < 0.01) compared with those in the control group. Moreover, the transcription and protein expression or phosphorylation levels of fecundity-related molecules, such as Akt, TOR, S6K, and Vg, were significantly decreased by capsaicin treatment. However, the effects disappeared between control group and CAP group after the TOR signaling pathway was inhibited by rapamycin.
CONCLUSIONS
Capsaicin can decrease the fecundity of An. stephensi by inhibiting the TOR signaling pathway. These data can help us to not only understand the effect of capsaicin on the reproductive ability of An. stephensi and its underlying mechanism, but also develop new efficient, safe, and pollution-free mosquito vector control agents.
Topics: Female; Humans; Mice; Animals; Anopheles; Malaria; Mosquito Vectors; Sirolimus; Capsaicin; Signal Transduction; Vitellogenins; Sugars
PubMed: 36510333
DOI: 10.1186/s13071-022-05593-0 -
PLoS Genetics Sep 2022Fecundity is arguably one of the most important life history traits, as it is closely tied to fitness. Most arthropods are recognized for their extreme reproductive...
Fecundity is arguably one of the most important life history traits, as it is closely tied to fitness. Most arthropods are recognized for their extreme reproductive capacity. For example, a single female of the oriental fruit fly Bactrocera dorsalis, a highly invasive species that is one of the most destructive agricultural pests worldwide, can lay more than 3000 eggs during its life span. The ovary is crucial for insect reproduction and its development requires further investigation at the molecular level. We report here that miR-309a is a regulator of ovarian development in B. dorsalis. Our bioinformatics and molecular studies have revealed that miR-309a binds the transcription factor pannier (GATA-binding factor A/pnr), and this activates yolk vitellogenin 2 (Vg 2) and vitellogenin receptor (VgR) advancing ovarian development. We further show that miR-309a is under the control of juvenile hormone (JH) and independent from 20-hydroxyecdysone. Thus, we identified a JH-controlled miR-309a/pnr axis that regulates Vg2 and VgR to control the ovarian development. This study has further enhanced our understanding of molecular mechanisms governing ovarian development and insect reproduction. It provides a background for identifying targets for controlling important Dipteran pests.
Topics: Animals; Drosophila; Ecdysterone; Female; Juvenile Hormones; MicroRNAs; Tephritidae; Transcription Factors; Vitellogenins
PubMed: 36112661
DOI: 10.1371/journal.pgen.1010411 -
Journal of Lipid Research Mar 2007Circulatory lipid transport in animals is mediated to a substantial extent by members of the large lipid transfer (LLT) protein (LLTP) superfamily. These proteins,... (Review)
Review
Circulatory lipid transport in animals is mediated to a substantial extent by members of the large lipid transfer (LLT) protein (LLTP) superfamily. These proteins, including apolipoprotein B (apoB), bind lipids and constitute the structural basis for the assembly of lipoproteins. The current analyses of sequence data indicate that LLTPs are unique to animals and that these lipid binding proteins evolved in the earliest multicellular animals. In addition, two novel LLTPs were recognized in insects. Structural and phylogenetic analyses reveal three major families of LLTPs: the apoB-like LLTPs, the vitellogenin-like LLTPs, and the microsomal triglyceride transfer protein (MTP)-like LLTPs, or MTPs. The latter are ubiquitous, whereas the two other families are distributed differentially between animal groups. Besides similarities, remarkable variations are also found among LLTPs in their major lipid-binding sites (i.e., the LLT module as well as the predicted clusters of amphipathic secondary structure): variations such as protein modification and number, size, or occurrence of the clusters. Strikingly, comparative research has also highlighted a multitude of functions for LLTPs in addition to circulatory lipid transport. The integration of LLTP structure, function, and evolution reveals multiple adaptations, which have come about in part upon neofunctionalization of duplicated genes. Moreover, the change, exchange, and expansion of functions illustrate the opportune application of lipid-binding proteins in nature. Accordingly, comparative research exposes the structural and functional adaptations in animal lipid carriers and brings up novel possibilities for the manipulation of lipid transport.
Topics: Animals; Apolipoproteins B; Carrier Proteins; Evolution, Molecular; Humans; Models, Molecular; Phylogeny; Protein Structure, Secondary; Vitellogenins
PubMed: 17148551
DOI: 10.1194/jlr.R600028-JLR200