首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Invasive meningococcal disease causes over 3500 cases each year in Europe, with particularly high incidence among young children. Among serogroup B meningococci, which cause most of the cases, high diversity in the outer membrane proteins (OMPs) is observed in endemic situations; however, comprehensive molecular epidemiological data are available for the diversity and distribution of the OMPs PorA and FetA and these can be used to rationally design a vaccine with high coverage of the case isolates. The aim of this study was to determine whether outer membrane vesicles (OMVs) derived from an isolate with constitutive FetA expression (MenPF-1 vaccine) could be used to induce antibodies against both the PorA and FetA antigens. The immunogenicity of various dose levels and number of doses was evaluated in mice and rabbits, and IgG antibody responses tested against OMVs and recombinant PorA and FetA proteins. A panel of four isogenic mutants was generated and used to evaluate the relative ability of the vaccine to induce serum bactericidal activity (SBA) against FetA and PorA. Sera from mice were tested in SBA against the four target strains. Results demonstrated that the MenPF-1 OMVs were immunogenic against PorA and FetA in both animal models. Furthermore, the murine antibodies induced were bactericidal against isogenic mutant strains, suggesting that antibodies to both PorA and FetA were functional. The data presented indicate that the MenPF-1 vaccine is a suitable formulation for presenting PorA and FetA OMPs in order to induce bactericidal antibodies, and that proceeding to a Phase I clinical trial with this vaccine candidate is justified.  相似文献   

2.

Background

The serogroup A conjugate meningococcal vaccine, MenAfriVac, was introduced in mass vaccination campaigns in December 2010 in Burkina Faso, Mali and Niger. In the coming years, vaccination will be extended to other African countries at risk of epidemics. To document the molecular characteristics of disease-causing meningococcal strains circulating in the meningitis belt of Africa before vaccine introduction, the World Health Organization Collaborating Centers on Meningococci in Europe and United States established a common strain collection of 773 isolates from cases of invasive meningococcal disease collected between 2004 and 2010 from 13 sub-Saharan countries.

Methodology

All isolates were characterized by multilocus sequence typing, and 487 (62%) were also analyzed for genetic variation in the surface antigens PorA and FetA. Antibiotic susceptibility was tested for part of the collection.

Principal Findings

Only 19 sequence types (STs) belonging to 6 clonal complexes were revealed. ST-5 clonal complex dominated with 578 (74.8%) isolates. All ST-5 complex isolates were remarkably homogeneous in their PorA (P1.20,9) and FetA (F3-1) and characterized the serogroup A strains which have been responsible for most epidemics during this time period. Sixty-eight (8.8%) of the 773 isolates belonged to the ST-11 clonal complex which was mainly represented by serogroup W135, while an additional 38 (4.9%) W135 isolates belonged to the ST-175 complex. Forty-eight (6.2%) serogroup X isolates from West Africa belonged to the ST-181 complex, while serogroup X cases in Kenya and Uganda were caused by an unrelated clone, ST-5403. Serogroup X, ST-181, emerged in Burkina Faso before vaccine introduction.

Conclusions

In the seven years preceding introduction of a new serogroup A conjugate vaccine, serogroup A of the ST-5 clonal complex was identified as the predominant disease-causing strain.  相似文献   

3.

Background

In 2002 a Meningococcal serogroup C (MenC) conjugate vaccine, with tetanus toxoid as carrier protein, was introduced in the Netherlands as a single-dose at 14 months of age. A catch-up campaign was performed targeting all individuals aged 14 months to 18 years. We determined the MenC-specific immunity before and after introduction of the MenC conjugate (MenCC) vaccine.

Methods and Findings

Two cross-sectional population-based serum banks, collected in 1995/1996 (n = 8539) and in 2006/2007 (n = 6386), were used for this study. The main outcome measurements were the levels of MenC polysaccharide(PS)-specific IgG and serum bactericidal antibodies (SBA) after routine immunization, 4–5 years after catch-up immunization or by natural immunity. There was an increasing persistence of PS-specific IgG and SBA with age in the catch-up immunized cohorts 4–5 years after their MenCC immunization (MenC PS-specific IgG, 0.25 µg/ml (95%CI: 0.19–0.31 µg/ml) at age 6 years, gradually increasing to 2.34 µg/ml,(95%CI: 1.70–3.32 µg/ml) at age 21–22 years). A comparable pattern was found for antibodies against the carrier protein in children immunized above 9 years of age. In case of vaccination before the age of 5 years, PS-specific IgG was rapidly lost. For all age-cohorts together, SBA seroprevalence (≥8) increased from 19.7% to 43.0% in the pre- and post-MenC introduction eras, respectively. In non-immunized adults the SBA seroprevalence was not significantly different between the pre- and post-MenC introduction periods, whereas PS-specific IgG was significantly lower in the post-MenC vaccination (GMT, age ≥25 years, 0.10 µg/ml) era compared to the pre-vaccination (GMT, age ≥25 years, 0.43 µg/ml) era.

Conclusion

MenCC vaccination administered above 5 years of age induced high IgG levels compared to natural exposure, increasing with age. In children below 14 months of age and non-immunized cohorts lower IgG levels were observed compared to the pre-vaccination era, whereas functional levels remained similar in adults. Whether the lower IgG poses individuals at increased risk for MenC disease should be carefully monitored. Large-scale introduction of a MenCC vaccine has led to improved protection in adolescents, but in infants a single-dose schedule may not provide sufficient protection on the long-term and therefore a booster-dose early in adolescence should be considered.  相似文献   

4.
本文将免疫沉淀法——免疫双扩散及对流免疫电泳法用于A群流脑多糖菌苗的鉴别试验。并对其检测A群流脑多糖菌苗的特异性及敏感性与传统采用的间接血凝抑制试验法进行了比较。试验结果表明,免疫沉淀法准确、特异性好、操作简便、经济。完全符合WHO规程及中国规程中对《A群脑膜炎球菌多糖菌苗制造及检定规程》鉴别试验的要求。因此可望替代现行的间接血凝抑制试验,以作为今后A群流脑多糖菌苗鉴别试验的常规测定法  相似文献   

5.
本文应用鲎试验凝胶法定量测定了212批A群流脑多糖菌苗中内毒素含量,并与家兔热原试验结果进行了比较,通过试验求得内毒素标准品对家兔体温升温变化关系的线性方程和内毒素对家兔最小致热剂量。结果表明,占检定总批数94.3%的制品中内毒素含量<100IU/μg多糖,家兔热原试验合格率为100%,5.7%的制品中内毒素含量≥100IU/μg多糖,家兔热原试验合格率为58.3%。根据实验结果,可制订用凝胶法替代家兔法进行A群流脑多糖菌苗的热原质试验的判定标准。作者建议:内毒素含量<100IU/μg多糖者,热原质试验判为合格,≥100IU/μg多糖者,用家兔法予以仲裁。  相似文献   

6.

Background

During a citywide epidemic of serogroup C meningococcal disease in Salvador in 2010, Brazil, the state government initiated mass vaccination targeting two age groups with high attack rates: individuals aged <5 years and 10–24 years. More than 600,000 doses of meningococcal serogroup C conjugate vaccines were administered. We performed a case-control study to evaluate vaccine uptake, document vaccine effectiveness and identify reasons for non-vaccination.

Methods and Findings

Population-based surveillance identified patients with laboratory-confirmed invasive meningococcal C (MenC) disease during 2010. Information on MenC vaccination was obtained from case patients and age-matched individuals from the same neighborhoods. MenC vaccine effectiveness was estimated based on the exact odds ratios obtained by conditional logistic regression analysis. Of 51 laboratory-confirmed cases of serogroup C meningococcal disease among patients <5 and 10–24 years of age 50 were included in the study and matched with 240 controls. Overall case-fatality was 25%. MenC vaccine coverage among controls increased from 7.1% to 70.2% after initiation of the vaccination campaign. None of the 50 case patients but 70 (29.2%) of the 240 control individuals, including 59 (70.2%) of 84 matched with cases from the period after MenC vaccination, had received at least one MenC vaccine dose. Overall effectiveness of MenC was 98% with a lower 95% exact confidence limit of 89%.

Conclusions

MenC vaccines administered during the meningococcal epidemic were highly effective, suggesting that rapid vaccine uptake through campaigns contributed to control of meningococcal disease.  相似文献   

7.
The binding of human complement inhibitors to vaccine antigens in vivo could diminish their immunogenicity. A meningococcal ligand for the complement down-regulator, factor H (fH), is fH-binding protein (fHbp), which is specific for human fH. Vaccines containing recombinant fHbp or native outer membrane vesicles (NOMV) from mutant strains with over-expressed fHbp are in clinical development. In a previous study in transgenic mice, the presence of human fH impaired the immunogenicity of a recombinant fHbp vaccine. In the present study, we prepared two NOMV vaccines from mutant group B strains with over-expressed wild-type fHbp or an R41S mutant fHbp with no detectable fH binding. In wild-type mice in which mouse fH did not bind to fHbp in either vaccine, the NOMV vaccine with wild-type fHbp elicited 2-fold higher serum IgG anti-fHbp titers (P = 0.001) and 4-fold higher complement-mediated bactericidal titers against a PorA-heterologous strain than the NOMV with the mutant fHbp (P = 0.003). By adsorption, the bactericidal antibodies were shown to be directed at fHbp. In transgenic mice in which human fH bound to the wild-type fHbp but not to the R41S fHbp, the NOMV vaccine with the mutant fHbp elicited 5-fold higher serum IgG anti-fHbp titers (P = 0.002), and 19-fold higher bactericidal titers than the NOMV vaccine with wild-type fHbp (P = 0.001). Thus, in mice that differed only by the presence of human fH, the respective results with the two vaccines were opposite. The enhanced bactericidal activity elicited by the mutant fHbp vaccine in the presence of human fH far outweighed the loss of immunogenicity of the mutant protein in wild-type animals. Engineering fHbp not to bind to its cognate complement inhibitor, therefore, may increase vaccine immunogenicity in humans.  相似文献   

8.
Microbial flocculation is a phenomenon of aggregation of dispersed bacterial cells in the form of flocs or flakes. In this study, the mechanism of spontaneous flocculation of Escherichia coli cells by overexpression of the bcsB gene was investigated. The flocculation induced by overexpression of bcsB was consistent among the various E. coli strains examined, including the K-12, B, and O strains, with flocs that resembled paper scraps in structure being about 1 to 2 mm. The distribution of green fluorescent protein-labeled E. coli cells within the floc structure was investigated by three-dimensional confocal laser scanning microscopy. Flocs were sensitive to proteinase K, indicating that the main component of the flocs was proteinous. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and nano-liquid chromatography tandem mass spectrometry analyses of the flocs strongly suggested the involvement of outer membrane vesicles (OMVs) in E. coli flocculation. The involvement of OMVs in flocculation was supported by transmission electron microscopy observation of flocs. Furthermore, bcsB-induced E. coli flocculation was greatly suppressed in strains with hypovesiculation phenotypes (ΔdsbA and ΔdsbB strains). Thus, our results demonstrate the strong correlation between spontaneous flocculation and enhanced OMV production of E. coli cells.  相似文献   

9.
We isolated a toluene-sensitive mutant, named mutant No. 32, which showed unchanged antibiotic resistance levels, from toluene-tolerant Pseudomonas putida IH-2000 by transposon mutagenesis with Tn5. The gene disrupted by insertion of Tn5 was identified as cyoC, which is one of the subunits of cytochrome o. The membrane protein, phospholipid, and lipopolysaccharide (LPS) of IH-2000 and that of mutant No. 32 were examined and compared. Some of the outer membrane proteins showed a decrease in mutant No. 32. The fatty acid components of LPS were found to be dodecanoic acid, 2-hydroxydodecanoic acid, 3-hydroxydodecanoic acid, and 3-hydroxydecanoic acid in both IH-2000 and No. 32; however, the relative proportions of these components differed in the two strains. Furthermore, cell surface hydrophobicity was increased in No. 32. These data suggest that mutation of cyoC caused the decrease in outer membrane proteins and the changing fatty acid composition of LPS. These changes in the outer membrane would cause an increase in cell surface hydrophobicity, and mutant No. 32 is considered to be sensitive to toluene.  相似文献   

10.
Anaplasma marginale is the causative agent of anaplasmosis in cattle. Transposon mutagenesis of this pathogen using the Himar1 system resulted in the isolation of an omp10 operon insertional mutant referred to as the omp10::himar1 mutant. The work presented here evaluated if this mutant had morphological and/or growth rate defects compared to wild-type A. marginale. Results showed that the morphology, developmental cycle, and growth in tick and mammalian cell cultures are similar for the mutant and the wild type. Tick transmission experiments established that tick infection levels with the mutant were similar to those with wild-type A. marginale and that infected ticks successfully infected cattle. However, this mutant exhibited reduced infectivity and growth in cattle. The possibility of transforming A. marginale by transposon mutagenesis coupled with in vitro and in vivo assessment of altered phenotypes can aid in the identification of genes associated with virulence. The isolation of deliberately attenuated organisms that can be evaluated in their natural biological system is an important advance for the rational design of vaccines against this species.  相似文献   

11.
Since the concentration of free iron in the human host is low, efficient iron-acquisition mechanisms constitute important virulence factors for pathogenic bacteria. In Gram-negative bacteria, TonB-dependent outer membrane receptors are implicated in iron acquisition. It is far less clear how other metals that are also scarce in the human host are transported across the bacterial outer membrane. With the aim of identifying novel vaccine candidates, we characterized in this study a hitherto unknown receptor in Neisseria meningitidis. We demonstrate that this receptor, designated ZnuD, is produced under zinc limitation and that it is involved in the uptake of zinc. Upon immunization of mice, it was capable of inducing bactericidal antibodies and we could detect ZnuD-specific antibodies in human convalescent patient sera. ZnuD is highly conserved among N. meningitidis isolates and homologues of the protein are found in many other Gram-negative pathogens, particularly in those residing in the respiratory tract. We conclude that ZnuD constitutes a promising candidate for the development of a vaccine against meningococcal disease for which no effective universal vaccine is available. Furthermore, the results suggest that receptor-mediated zinc uptake represents a novel virulence mechanism that is particularly important for bacterial survival in the respiratory tract.  相似文献   

12.
Chlamydia trachomatis is a major bacterial pathogen throughout the world. Although antibiotic therapy can be implemented in the case of early detection, a majority of the infections are asymptomatic, requiring the development of preventive measures. Efforts have focused on the production of a vaccine using the C. trachomatis major outer membrane protein (MOMP). MOMP is purified in its native (n) trimeric form using the zwitterionic detergent Z3–14, but its stability in detergent solutions is limited. Amphipols (APols) are synthetic polymers that can stabilize membrane proteins (MPs) in detergent-free aqueous solutions. Preservation of protein structure and optimization of exposure of the most effective antigenic regions can avoid vaccination with misfolded, poorly protective protein. Previously, we showed that APols maintain nMOMP secondary structure and that nMOMP/APol vaccine formulations elicit better protection than formulations using either recombinant or nMOMP solubilized in Z3–14. To achieve a greater understanding of the structural behavior and stability of nMOMP in APols, we have used several spectroscopic techniques to characterize its secondary structure (circular dichroism), tertiary and quaternary structures (immunochemistry and gel electrophoresis) and aggregation state (light scattering) as a function of temperature and time. We have also recorded NMR spectra of 15N-labeled nMOMP and find that the exposed loops are detectable in APols but not in detergent. Our analyses show that APols protect nMOMP much better than Z3–14 against denaturation due to continuous heating, repeated freeze/thaw cycles, or extended storage at room temperature. These results indicate that APols can help improve MP-based vaccine formulations.  相似文献   

13.

Background

Protective immunity against cholera is serogroup specific. Serogroup specificity in Vibrio cholerae is determined by the O-specific polysaccharide (OSP) of lipopolysaccharide (LPS). Generally, polysaccharides are poorly immunogenic, especially in young children.

Methodology

Here we report the evaluation in mice of a conjugate vaccine for cholera (OSP:TThc) made from V. cholerae O1 Ogawa O-Specific Polysaccharide–core (OSP) and recombinant tetanus toxoid heavy chain fragment (TThc). We immunized mice intramuscularly on days 0, 21, and 42 with OSP:TThc or OSP only, with or without dmLT, a non-toxigenic immunoadjuvant derived from heat labile toxin of Escherichia coli.

Principal Findings

We detected significant serum IgG antibody responses targeting OSP following a single immunization in mice receiving OSP:TThc with or without adjuvant. Anti-LPS IgG responses were detected following a second immunization in these cohorts. No anti-OSP or anti-LPS IgG responses were detected at any time in animals receiving un-conjugated OSP with or without immunoadjuvant, and in animals receiving immunoadjuvant alone. Responses were highest following immunization with adjuvant. Serum anti-OSP IgM responses were detected in mice receiving OSP:TThc with or without immunoadjuvant, and in mice receiving unconjugated OSP. Serum anti-LPS IgM and vibriocidal responses were detected in all vaccine cohorts except in mice receiving immunoadjuvant alone. No significant IgA anti-OSP or anti-LPS responses developed in any group. Administration of OSP:TThc and adjuvant also induced memory B cell responses targeting OSP and resulted in 95% protective efficacy in a mouse lethality cholera challenge model.

Conclusion

We describe a protectively immunogenic cholera conjugate in mice. Development of a cholera conjugate vaccine could assist in inducing long-term protective immunity, especially in young children who respond poorly to polysaccharide antigens.  相似文献   

14.

Background

Elderly people do not mount strong immune responses to vaccines. We compared 23-valent capsular polysaccharide (23vPPV) alone versus 7-valent conjugate (PCV7) vaccine followed by 23vPPV 6 months later in hospitalized elderly.

Methods

Participants were randomized to receive 23vPPV or PCV7-23vPPV. Antibodies against serotypes 3, 4, 6A, 6B, 9V, 14, 18C, 19A, 19F, 23F were measured by enzyme-linked immunosorbent (ELISA) and opsonophagocytic (OPA) assays at baseline, 6 months and 12 months.

Results

Of 312 recruited, between 40% and 72% of subjects had undetectable OPA titres at baseline. After one dose, PCV7 recipients had significantly higher responses to serotypes 9V (both assays) and 23F (OPA only), and 23vPPV recipients had significantly higher responses to serotype 3 (ELISA), 19F and 19A (OPA only). In subjects with undetectable OPA titres at baseline, a proportionately greater rise in OPA titre (P<0.01) was seen for all serotypes after both vaccines. The GMT ratio of OPA was significantly higher at 12 months in the PCV7-23vPPV group for serotypes 6A, 9V, 18C and 23F. OPA titre levels for these serotypes increased moderately after 6 months, whereas immunity waned in the 23vPPV only arm.

Conclusion

We did not show overwhelming benefit of one vaccine over the other. Low baseline immunity does not preclude a robust immune response, reiterating the importance of vaccinating the frail elderly. A schedule of PCV7-23vPPV prevents waning of antibody, suggesting that both vaccines could be useful in the elderly. Follow up studies are needed to determine persistence of immunity.

Trial Registration

The Australian Clinical Trials Registry ACTRN12607000387426  相似文献   

15.
Membrane vesicles (MVs) of Porphyromonas gingivalis are regarded as an offensive weapon of the bacterium, leading to tissue deterioration in periodontal disease. Therefore, isolation of highly purified MVs is indispensable to better understand the pathophysiological role of MVs in the progression of periodontitis. MVs are generally isolated by a conventional method based on ultracentrifugation of the bacterial culture supernatant. However, the resulting MVs are often contaminated with co-precipitating bacterial appendages sheared from the live bacteria. Here, we report an intriguing property of P. gingivalis MVs–their ability to bind superparamagnetic beads coated with epoxy groups (SB-Epoxy). Analysis of fractions collected during the purification revealed that all MVs of five tested P. gingivalis stains bound to SB-Epoxy. In contrast, free fimbriae in the crude MV preparation did not bind to the SB-Epoxy. The SB-Epoxy-bound MVs were easily dissociated from the SB-Epoxy using a mild denaturation buffer. These results suggest that the surface chemistry conferred by epoxy on the beads is responsible for the binding, which is mediated by noncovalent bonds. Both the structural integrity and purity of the isolated MVs were confirmed by electron microscopy. The isolated MVs also caused cell detachment from culture dishes at a physiologically relevant concentration. Assays of competitive binding between the SB-Epoxy and mixtures of MVs from five bacterial species demonstrated that only P. gingivalis MVs could be selectively eliminated from the mixtures. We suggest that this novel approach enables efficient purification and selective elimination of P. gingivalis MVs.  相似文献   

16.
17.
BackgroundCurrently in Japan, both 23-valent pneumococcal polysaccharide vaccine (PPSV–23) and 13-valent pneumococcal conjugate vaccine (PCV–13) are available for the elderly for the prevention of S. pneumoniae-related diseases. PPSV–23 was approved in 1988, while the extended use of PCV–13 was approved for adults aged 65 and older in June 2014. Despite these two vaccines being available, the recently launched national immunisation programme for the elderly only subsidised PPSV–23. The framework of the current immunisation programme lasts for five years. The elderly population eligible for the subsidised PPSV–23 shot for the 1st year are those aged 65, 70, 75, 80, 85, 90, 95 and ≥100. While from the 2nd year to the 5th year, those who will age 65, 70, 75, 80, 85, 90, 95 and 100 will receive the same subsidised shot.MethodsWe performed economic evaluations to (1) evaluate the efficiency of alternative strategies of PPSV–23 single-dose immunisation programme, and (2) investigate the efficiency of PCV–13 inclusion in the list for single-dose pneumococcal vaccine immunisation programme. Three alternative strategies were created in this study, namely: (1) current PPSV–23 strategy, (2) 65 to 80 (as “65–80 PPSV–23 strategy”), and (3) 65 and older (as “≥65 PPSV–23 strategy”). We constructed a Markov model depicting the S. pneumoniae-related disease course pathways. The transition probabilities, utility weights to estimate quality adjusted life year (QALY) and disease treatment costs were either calculated or cited from literature. Cost of per shot of vaccine was ¥8,116 (US$74; US$1 = ¥110) for PPSV–23 and ¥10,776 (US$98) for PCV–13. The model runs for 15 years with one year cycle after immunisation. Discounting was at 3%.ResultsCompared to current PPSV–23 strategy, 65–80 PPSV–23 strategy cost less but gained less, while the incremental cost-effectiveness ratios (ICERs) of ≥65 PPSV–23 strategy was ¥5,025,000 (US$45,682) per QALY gained. PCV–13 inclusion into the list for single-dose subsidy has an ICER of ¥377,000 (US$3,427) per QALY gained regardless of the PCV–13 diffusion level. These ICERs were found to be cost-effective since they are lower than the suggested criterion by WHO of three times GDP (¥11,000,000 or US$113,636 per QALY gained), which is the benchmark used in judging the cost-effectiveness of an immunisation programmne.ConclusionsThe results suggest that switching current PPSV–23 strategy to ≥65 PPSV–23 strategy or including PCV–13 into the list for single-dose subsidy to the elderly in Japan has value for money.  相似文献   

18.
19.
The ATP-dependent establishment of a positive membrane potential (measured as S14CN-accumulation) in membrane vesicles isolated from the roots of Atriplex nummularia Lindl. was not inhibited by NaMes and KMes at concentrations up to 140 millimolar. On the other hand, the formation of ΔpH (measured as 14C-methylamine accumulation or quenching of quinacrine fluorescence), was depressed by NaMes concentrations as low as 30 millimolar. Supply of NaMes after the ΔpH had been established brought about partial dissipation within 30 seconds. Extent of dissipation of ΔpH increased with NaMes concentration over the range tested (up to 180 millimolar). The H+/Na+ exchange indicated by these results was not due to the creation of a Na+ diffusion potential. Formation of ΔpH in these vesicles was stable to NO3 up to 100 millimolar; further, the dissipating effect of Na+ supply was apparent on a ΔpH formed in the presence of 30 millimolar NO3. Additional evidence that the origin of the membrane vesicles observed in this investigation was not the tonoplast and was probably the plasmalemma included the vanadate sensitivity of the establishment of the membrane potential.  相似文献   

20.
A special group of mitochondrial outer membrane (MOM) proteins spans the membrane several times via multiple helical segments. Such multispan proteins are synthesized on cytosolic ribosomes before their targeting to mitochondria and insertion into the MOM. Previous work recognized the import receptor Tom70 and the mitochondrial import (MIM) complex, both residents of the MOM, as required for optimal biogenesis of these proteins. However, their involvement is not sufficient to explain either the entire import pathway or its regulation. To identify additional factors that are involved in the biogenesis of MOM multispan proteins, we performed complementary high-throughput visual and growth screens in Saccharomyces cerevisiae. Cardiolipin (CL) synthase (Crd1) appeared as a candidate in both screens. Our results indeed demonstrate lower steady-state levels of the multispan proteins Ugo1, Scm4, and Om14 in mitochondria from crd1Δ cells. Importantly, MOM single-span proteins were not affected by this mutation. Furthermore, organelles lacking Crd1 had a lower in vitro capacity to import newly synthesized Ugo1 and Scm4 molecules. Crd1, which is located in the mitochondrial inner membrane, condenses phosphatidylglycerol together with CDP-diacylglycerol to obtain de novo synthesized CL molecules. Hence, our findings suggest that CL is an important component in the biogenesis of MOM multispan proteins.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号