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1.
Hagit Hak Hagai Raanan Shahar Schwarz Yifat Sherman Savithramma P. Dinesh-Kumar Ziv Spiegelman 《Molecular Plant Pathology》2023,24(8):838-848
The tomato Tm-22 gene was considered to be one of the most durable resistance genes in agriculture, protecting against viruses of the Tobamovirus genus, such as tomato mosaic virus (ToMV) and tobacco mosaic virus (TMV). However, an emerging tobamovirus, tomato brown rugose fruit virus (ToBRFV), has overcome Tm-22, damaging tomato production worldwide. Tm-22 encodes a nucleotide-binding leucine-rich repeat (NLR) class immune receptor that recognizes its effector, the tobamovirus movement protein (MP). Previously, we found that ToBRFV MP (MPToBRFV) enabled the virus to overcome Tm-22-mediated resistance. Yet, it was unknown how Tm-22 remained durable against other tobamoviruses, such as TMV and ToMV, for over 60 years. Here, we show that a conserved cysteine (C68) in the MP of TMV (MPTMV) plays a dual role in Tm-22 activation and viral movement. Substitution of MPToBRFV amino acid H67 with the corresponding amino acid in MPTMV (C68) activated Tm-22-mediated resistance. However, replacement of C68 in TMV and ToMV disabled the infectivity of both viruses. Phylogenetic and structural prediction analysis revealed that C68 is conserved among all Solanaceae-infecting tobamoviruses except ToBRFV and localizes to a predicted jelly-roll fold common to various MPs. Cell-to-cell and subcellular movement analysis showed that C68 is required for the movement of TMV by regulating the MP interaction with the endoplasmic reticulum and targeting it to plasmodesmata. The dual role of C68 in viral movement and Tm-22 immune activation could explain how TMV was unable to overcome this resistance for such a long period. 相似文献
2.
Production of indirect TNP-specific plaque-forming cells (PFC) in response to immunization with 2, 4, 6-trinitrophenyl (TNP) conjugated to autogenous mouse serum albumin (MSA) in complete Freund's adjuvant (CFA) is underH-2 control. On the C57BL/10 (B10) background,H-2
b andH-2
d
strains of mice are high responders, whereasH-2
a
,H-2
k
orH-2
y2
strains yield low levels of indirect TNP-specific PFC. An unusual pattern of inheritance has been revealed in B10 congenic mice: high responsiveness controlled byH-2
b
is inherited recessively, while high responsiveness controlled byH-2
d
is inherited dominantly. On the C3H and A strain backgrounds, high responsiveness controlled byH-2
b
is partially recessive;H-2
b
/H-2
a
F1 mice respond with 20%-40% of the high responderH-2
b
response. Yet, high responsiveness controlled by theH-2
d
haplotype remains dominant on the C3H background. A hierarchy of haplotypes in order of decreasing immune responsiveness to TNP-MSA is evident as follows:H-2
d
>H-2
b
>H-2
k
,H-2
a
orH-2
y2
. The unusual patterns of inheritance in the TNP-MSA system reveal graded regulation of responsiveness attributable to bothH-2 and non-H-2 genes. 相似文献
3.
We isolated and characterized a nickel (Ni2+)-resistant mutant (GA1) of Schizosaccharomyces pombe. This mutant strain displayed resistance to both Ni2+ and Zn2+, but not to Cd2+, Co2+, and Cu2+. The growth rate of GA1 increased proportionally with increasing Mg2+ concentrations until 50 mM Mg2+. The GA1 mutation phenotype suggests a defect in Mg2+ uptake. Sequence analysis of the GA1 open reading frame (ORF) O13779, which is homologous to the prokaryotic and eukaryotic CorA Mg2+ transport systems, revealed a point mutation at codon 153 (ccc to acc) resulting in a Pro 153Thr substitution in the N-terminus
of the CorA domain. Our results provide novel genetic information about Ni2+ resistance in fission yeast. Specifically, that reducing Mg2+ influx through the CorA Mg2+ transport membrane protein confers Ni2+ resistance in S. pombe. We also report that Ni2+ ion detoxification of the fission yeast is related to histidine metabolism and pH. 相似文献
4.
The antibody response to the hapten 2,4,6-trinitrophenyl (TNP) conjugated to autogenous mouse serum albumin (MSA) is regulated by anIr gene(s) located within the major histocompatibility complex (MHC). Both the qualitative and quantitative ability of congenic strains to produce TNP-specific antibodies are functions of theH-2 haplotype. Thus, mouse strains may be classified as high (H-2
d), intermediate (H-2
b,H-2
s), and low responders (H-2
a,H-2
k,H-2
n,H-2
p,H-2
q). Antibody responses, as measured by antigen-binding capacities in modified Farr assays, were compared among strains carrying recombinantH-2 haplotypes and their hybrid progenies. Distinct high- and low-responder phenotypes were evident throughout the time course of both primary and secondary antibody responses. The gene locus controlling specific responsiveness to TNP-MSA, now designatedIr-6, was mapped within theI-B subregion of theH-2 complex. Recessive inheritance of high responsiveness was confirmed in hybrid progenies of three different low × high-responder crosses. 相似文献
5.
Bishnu P. Mukhopadhyay Hridoy R. Bairagya 《Journal of biomolecular structure & dynamics》2013,31(4):637-638
Abstract Conformational preferences of the hypermodified nucleic acid bases N6-(Δ2 -cis-hydroxyisopentenyl)adenine, cis-io6Ade also known as cis-zeatin, and N6-(Δ2 -trans-hydroxyisopentenyl)adenine, trans-io6ade or trans-zeatin, and 2-methylthio derivatives of these cis-ms2io6Ade or cis-ms2zeatin, and trans-ms2io6Ade or trans-ms2zeatin have been investigated theoretically by the quantum chemical Perturbative Configuration Interaction with Localized Orbitals (PCILO) method. Automated geometry optimization using quantum chemical MNDO, AMI and PM3 methods has also been made to compare the salient features. The predicted most stable conformation of cis-io6Ade, trans-io6Ade, cis-ms2io6Ade and trans-ms2io6Ade are such that in each of these molecules the isopentenyl substituent spreads away (has “dista” conformation) from the five membered ring imidazole moiety of the adenine. The atoms N(6), C(10) and C(11) remain coplanar with the adenine ring in the predicted preferred conformation for each of these molecules. In cis-io6Ade as well as cis- ms2io6Ade the hydroxyl oxygen may participate in intramolecular hydrogen bonding with the H-C(10)-H group. In trans-io6Ade the hydroxyl group is oriented towards the H-C(2) instead. This orientation is retained in trans-ms2io6Ade, possible O-H…S hydrogen bonding may be a stabilizing factor. In all these four modified adenines C(11)-H is favourably placed to participate in intramolecular hydrogen bonding with N(1). In cis-ms2io6Ade as well as trans-ms2io6Ade the 2-methylthio group preferentially orients on the same side as C(2)-N(3) bond, due to this nonobstrusive placing, orientation of the hydroxyisopentenyl substituent remains unaffected by 2-methylthiolation. Thus the N(1) site remains shielded irrespective of the 2-methylthiolation status in these various cis-and trans-zeatin analogs alike. Firmly held orientation of hydroxyisopentenyl substituent in zeatin isomers and derivatives, in contrast to adaptable orientation of isopentenyl substituent in i6Ade and ms2i6Ade, may account for the increased efficiency of suppressor tRNA and reduced codon context sensitivity accompanied with the occurrence of ms2-zeatin (ms2io6Ade) modification. 相似文献
6.
The differential expression of H-2 specificities recognized by antibody and by cytotoxic T lymphocytes (CTL) has been studied using a clone (FY7) of the C57BL/6 leukemia cell line FBL-3 (H-2
b
/H-2
b
). Unlike C57BL/10 spleen cells, EL-4 lymphoma cells and Y57-2C leukemia cells (allH-2
b
/H-2
b
), FY7 failed to induce the primary in vitro generation of anti-H-2b CTL by (B10.A x A)F1 (H-2
a
/H-2
a
or (B10.D2 x BALB/c)F1 (H-2
d
/H-2
d
) responder spleen cells. In addition, FY7 was not lysed by, and did not competitively inhibit anti-H-2b CTL. Quantitative absorption tests with H-2Kb and H-2Db antisera revealed that FY7 expressed these antigens in quantitatively similar amounts to EL-4. The H-2Kb product of FY7 appeared to be identical with that of C57BL/10 spleen cells both in apparent molecular weight and isoelectric point. Yet FY7 failed to inhibit anti-H-2Kb CTL competitively in a cold target inhibition assay. Possible mechanisms are discussed for the lack of T-lymphocyte recognition of the H-2Kb-gene product expressed by FY7.Abbreviations used in this paper CTL
cytotoxic T lymphocytes
- MHC
major histocompatibility complex
- MLC
mixed lymphocyte culture
- PAGE
polyacrylamide gel electrophoresis 相似文献
7.
Chiaraluce Moretti Simone Trabalza Letizia Granieri Eloy Caballo-Ponce Giulia Devescovi Alberto Marco Del Pino Cayo Ramos Vittorio Venturi Harrold A. van den Burg Roberto Buonaurio Carlo Alberto Palmerini 《Molecular Plant Pathology》2019,20(5):716-730
In a number of compatible plant-bacterium interactions, a rise in apoplastic Ca2+ levels is observed, suggesting that Ca2+ represents an important environmental clue, as reported for bacteria infecting mammalians. We demonstrate that Ca2+ entry in Pseudomonas savastanoi pv. savastanoi (Psav) strain DAPP-PG 722 is mediated by a Na+/Ca2+ exchanger critical for virulence. Using the fluorescent Ca2+ probe Fura 2-AM, we demonstrate that Ca2+ enters Psav cells foremost when they experience low levels of energy, a situation mimicking the apoplastic fluid. In fact, Ca2+ entry was suppressed in the presence of high concentrations of glucose, fructose, sucrose or adenosine triphosphate (ATP). Since Ca2+ entry was inhibited by nifedipine and LiCl, we conclude that the channel for Ca2+ entry is a Na+/Ca2+ exchanger. In silico analysis of the Psav DAPP-PG 722 genome revealed the presence of a single gene coding for a Na+/Ca2+ exchanger (cneA), which is a widely conserved and ancestral gene within the P. syringae complex based on gene phylogeny. Mutation of cneA compromised not only Ca2+ entry, but also compromised the Hypersensitive response (HR) in tobacco leaves and blocked the ability to induce knots in olive stems. The expression of both pathogenicity (hrpL, hrpA and iaaM) and virulence (ptz) genes was reduced in this Psav-cneA mutant. Complementation of the Psav-cneA mutation restored both Ca2+ entry and pathogenicity in olive plants, but failed to restore the HR in tobacco leaves. In conclusion, Ca2+ entry acts as a ‘host signal’ that allows and promotes Psav pathogenicity on olive plants. 相似文献
8.
Maria I. C. Sampaio Maria P. C. Schneider Carmem M. L. Barroso Barbara T. F. Silva Horacio Schneider Filomeno Encarnacion Enrique Montoya Francisco M. Salzano 《International journal of primatology》1991,12(4):389-402
Carbonic anhydrase II electrophoretic patterns were investigated in 3113 animals belonging to 12 genera and 24 species of
New World primates. Polymorphism was detected in 13 species. A total of 24 different alleles was postulated to explain the
variability found; the genusAotus showed the highest (eight) number of such alleles. Three genera of the family Callitrichidae (Callithrix, Saguinus, andCebuella) presented five alleles that were not found among the Cebidae. Important markers at the generic level were observed inCallicebus (CA2
*6 andCA2
*12),Cebus (CA2
*10, CA2*16, andCA2
*21), andAotus (CA2*3, CA2*4, CA2*5, CA2*9, CA2*15, CA2*17, CA2*22, CA2*23). CA2*13 seems to be the most common allele among the Cebidae; six genera of this family showed frequencies higher than 70% of it. 相似文献
9.
The H-2L
d
allele has been identified by others as the sole Ir gene in the H-2
d
haplotype for the cytotoxic T lymphocyte (CTL) response to mouse lymphocytic choriomeningitis virus (LCMV). The BALB/c-H-2
dm2
(C-H-2
dm2
) mutant lacks H-2L
d
, and thus should be ideal for assessing the contribution of virus-immune CTL to LCM immunopathology. Comparison of the C-H-2 dm2 mice with congenic BALB/c mice revealed that there is a delay of about 24 h in the onset of severe inflammatory process and symptoms in the mutant strain, but the absence of H-2L
d
did not prevent the later development of fatal disease in mice injected intracerebrally (i.e.) with neurotropic LCMV. This could indicate that virus-immune CTL are not the major mediators of clinical LCM. Spleen cells from LCMV-primed BALB/c mice did not show CTL activity for LCMV-infected C3H.OH, C-H-2
dm2
, or (CBA × C-H-2
dm2
)F1 target cells. However, immune lymphocytes from both the mutant and the F1 strains lyse virus-infected BALB/c cells. Furthermore, BtO.HTG and, in some experiments, B10.A(5R) mice generated CTL lytic for LCMV-infected BALB/c, C-H-2
dm2
, and (CBA × CH-2
dm2
)F1 macrophages. Apparently H-2L
d
is immunodominant in the H-2d restricted response to LCMV. However, in the absence of H-2L
d
, it seems that H-2K
d
and, to a lesser extent, H-2D
d
also serve as Ir genes for the CTL response in this infection. Even so, the absence of the H-2Ld-restricting element results in a disease process which is either delayed in onset or less severe. 相似文献
10.
Lymphocytes from chickens homozygous (B
2
B
2) at the major histocompatibility complex (MHC) were tested for cytotoxic activity against five types of target chicken embryo fibroblasts (CEF). Lymphocytes from B2B2 chickens bearing RSV-induced tumors lysed in vitro targets of B
2
B
2 and B
5
B
5 RSV-infected CEF and B
5
B
5 normal CEF, but did not lyse B
2
B
2 and B
24
B
24 normal CEF. Lymphocytes from normal B
2
B
2 chickens did not lyse any of the five types of CEF targets. Alloantisera absorption studies showed that both RSV-infected and uninfected CEF shared alloantigens, in particular B-F alloantigens, with syngeneic erythrocytes. Absorption with B
2
B
2 RSV-infected CEF significantly lowered the titer of B
2
B
2 anti-B
5
B
5 alloantisera. Cross-reactivity between B
5 antigen(s) and tumor-associated antigen was suggested and the nature of the cross-reactivity was discussed. It is hypothesized that this cross-reactivity prevents B
5
B
5 chickens from recognizing RSV-induced tumors as foreign, enhances tumor growth and leads to death of the host. 相似文献
11.
The D region of the H-2
d
haplotype contains five class I genes: H-2D
d
, D2
d
, D3
d
, D4
d
and H-2L
d
. Although previous studies have suggested the presence of D-end encoded class I molecules in addition to H-2Dd and H-2Ld, segregation of genes encoding such molecules has not been demonstrated. In this report we have used cãtotoxic T lymphocytes (CTL) to examine the D region of the H-2
d
haplotype for the presence of additional class I molecules. CTL generated in (C3H × B6.K1)F1 (K
k
D
k
, K
b
D
b
) mice against the hybrid class I gene product Q10d/Ld expressed on L cells cross-react with H-2Ld but not H-2Dd molecules, as determined by lysis of transfected cells expressing H-2Ld but not H-2Dd. Although H-2Ld-specific monoclonal antibodies (mAb) completely inhibit H-2Ld-specific CTL from killing B10.A(3R) (K
b
D
d
L
d
) target cells, only partial inhibition of anti-Q10 CTL-mediated lysis was observed, suggesting the presence of an additional D-end molecule as a target for these latter CTL. To identify the region containing the gene encoding the Q10 cross-reactive molecule, we show that anti-Q10 CTL lyse target cells from a D-region recombinant strain B10.RQDB, which has H-2D
d
, D2
d
, D3
d
, D4
d
, and H-2D
b
but not the H-2L
d
H-2
d
, and H-2L
d
(including D2
d
, D3
d
, and D4
d
, lacks this anti-Q10 CTL target molecule. Together, these data demonstrate that a class I gene mapping between H-2D
d
and H-2L
d
encodes an antigen recognozed by anti-Q10 CTL. A likely candidate for this gene is D2
d
, D3
d
or D4
d
. 相似文献
12.
Teratogenic development in chicken embryos associated with a major deletion in the rRNA gene cluster 总被引:1,自引:0,他引:1
A new strain of chickens (mPNU) that segregates a severely deleted rDNA cluster was studied. Individuals heterozygous (+/p2) and homozygous (p2/p2) for the deletion were found to have 56 and 27%, respectively, of the normal complement of rRNA genes (290 copies/cell). Morphogenesis, cellular rRNA levels, and nucleolar sizes, were investigated and compared in normal +/+, +/p2, and p2/p2 embryos. Cellular rRNA contents were similar among the three genotypes at stage X, but subsequently during gastrulation, p2/p2 levels were reduced to 56% and eventually to 43% of +/+. Viability and morphogenesis were normal in p2/p2 embryos until the initial primitive streak stage of gastrulation. However, further development was abnormal and characterized by disrupted axis formation. In +/+ and +/p2 embryos, rRNA levels and nucleolar sizes increased during early development; however, the profile of these increases differed temporally and quantitatively between the genotypes. The +/p2 embryos, at the full streak stage of gastrulation, exhibited reduced rRNA levels and nucleolar sizes (80% of +/+), yet the +/p2 embryos developed normally. These studies establish a minimum copy number requirement lower than previously demonstrated, that is, a rDNA genotype with only 56% of the normal gene complement (~160 genes) is compatible with early embryonic viability. Also, a rRNA threshold was detected: rRNA levels that were 56% of +/+ failed to support normal gastrulation; however, even under the circumstance of reduced rRNA levels (43% of control), some aspects of gastrulation apparently continue (cell migration and invagination). The teratogenic development of p2/p2 embryos is a biological consequence unique from that found in other metazoan models of rDNA-deficiency, and will be useful as a model to investigate mechanisms of vertebrate gastrulation and axis formation. 相似文献
13.
The level of cell proliferation and interleukin-2 (IL-2) production observed in an anti-Mls mixed lymphocyte reaction between spleen cells from H-2 compatible, Mls incompatible mouse strains is determined by the H-2 haplotype of the mouse combination. Thus, while AKR (H-2
k) spleen cells stimulated strong M1sa responses in H-2k responder cells, AKR H-2b spleen cells stimulated no or negligible M1sa responses in responder cells from H-2
bmouse strains. This effect was observed at the levels of IL-2 production and cell proliferation. The magnitude of the response observed using F1 (H-2
k/H-2
b) responder cells was found to be a function of stimulator rather than responder cells. The poor stimulatory capacity of AKRH-2
bspleen cells was also shown not to be due to the loss of the stimulatory Mls
aallele during the construction of the congenic strain from AKR and C57BL/6 parental strains. Using stimulator cells from a second series of congenic mice, we found H-2
b(strain DLLP) again to represent a poorly Mlsa stimulatory H-2 haplotype. In addition, H-2q (DBA/1) cells displayed very poor Mlsa stimulatory potential while H-2d (D1.C) cells were efficient Mlsa stimulators. Again the effect was shown to be at the level of the stimulator cells. In toto, our findings indicate that the H-2
kand H-2
dhaplotypes encode strong Mlsa stimulatory potential while the H-2
band H-2
qhaplotypes determine poor Mlsa stimulatory potential in primary in vitro responses, measured as cell proliferation and IL-2 production.Abbreviations used in this paper: CTL
cytotoxic T lymphocyte
- IL-1
interleukin-1
- IL-2
interleukin-2
- MLR
mixed lymphocyte reaction
- NMS
normal mouse serum 相似文献
14.
Allometric relationships for estimating the phytomass of aboveground organs (stem, branches, leaves and their sum) and the leaf area in the mangrove Kandelia candel (L.) Druce were investigated. The variable D0.12H (D0.1 stem diameter at a height of H/10, H tree height) showed better accuracy of estimation than D2 (D, DBH) or D2H. A moderate relationship was found when the branch weight, leaf weight and leaf area were plotted against DB2 (DB stem diameter at a height of clear bole length). A strong linear relationship was found between leaf area and leaf weight (R2=0.979). The aboveground weight (wT) showed a strong relationship when plotted against D0.12H (R2=0.958), but very weak relationships were obtained against D2 (R2=0.300) and D2H (R2=0.316). The wT also showed a proportional relationship (R2=0.978) to D0.12H with a proportional constant of 0.04117 kg cm–2 m–1 (R2=0.978). Taking into account the allometric relationships of the weight of aboveground organs or leaf area per tree to different dimensions, such as D2, D2H, DB2 and D0.12H, a standard procedure for estimating the biomass and leaf area index in the K. candel stand, including the shorter trees, is proposed. 相似文献
15.
Cell-mediated lympholysis (CML) reactions were studied among four strains of C57BL/6 (B6) mice carrying mutant alleles (H-2
ba
,H-2
bd
,H-2
bg
, andH-2
bh
) at thez1 locus in theK end ofH-2
b
and the original B6 (H-2
b
) strain. Cross killing of target cells from lines that had not participated in the mixed lymphocyte reaction (MLR) was extensive, but usually less intense than that of target cells of stimulator cell genotype. The extent of CML crossreactivity could be limited by using cells from F1 hybrid mice as responders in MLR. In a comprehensive analysis of the cytotoxicity exerted by 20 MLR combinations with homozygous, and 10 MLR combinations with F1 hybrid responder cells, 19 different CML cytotoxicity patterns were identified, corresponding to at least 19 different CML target specificites. When the number of CML mismatches of each mutant with the originalH-2
b
was calculated,H-2
ba
was found to be most distinct fromH-2
b
,H-2
bs
andH-2
bd
were closest toH-2
b
, andH-2
bh
occupied an intermediate position. The validity of this sequence of relatedness is supported by published reports on skin graft survival times and on the interaction of T lymphocytes with virus-infected target cells using cells fromz1 locus mutants. 相似文献
16.
Osmotic Swelling-Induced Changes in Cytosolic Calcium Do Not Affect Regulatory Volume Decrease in Rat Cultured Suspended Cerebellar Astrocytes 总被引:2,自引:1,他引:1
Sandra Morales-Mulia Luis Vaca Arturo Hernandez-Cruz Herminia Pasantes-Morales 《Journal of neurochemistry》1998,71(6):2330-2338
Abstract: Hyposmotic swelling-induced changes in intracellular Ca2+ concentration ([Ca2+]i) and their influence on regulatory volume decrease (RVD) were examined in rat cultured suspended cerebellar astrocytes. Hyposmotic media (50 or 30%) evoked an immediate rise in [Ca2+]i from 117 nM to a mean peak increase of 386 (50%) and 220 nM (30%), followed by a maintained plateau phase. Ca2+ influx through the plasmalemma as well as release from internal stores contributed to this osmosensitive [Ca2+]i elevation. Omission of external Ca2+ or addition of Cd2+, Mn2+, or Gd3+ did not reduce RVD, although it was decreased by La3+ (0.1–1 mM). Verapamil did not affect either the swelling-evoked [Ca2+]i or RVD. Maneuvers that deplete endoplasmic reticulum (ER) Ca2+ stores, such as treatment (in Ca2+-free medium) with 0.2 µM thapsigargin (Tg), 10 µM 2,5-di-tert-butylhydroquinone, 1 µM ionomycin, or 100 µM ATP abolished the increase in [Ca2+]i but did not affect RVD. However, prolonged exposure to 1 µM Tg blocked RVD regardless of ER Ca2+ content or cytosolic Ca2+ levels. Ryanodine (up to 100 µM) and caffeine (10 mM) did not modify [Ca2+]i or RVD. BAPTA-acetoxymethyl ester (20 µM) abolished [Ca2+]i elevation without affecting RVD, but at higher concentrations BAPTA prevented cell swelling and blocked RVD. We conclude that the osmosensitive [Ca2+]i rise occurs as a consequence of increased Ca2+ permeability of plasma and organelle membranes, but it appears not relevant as a transduction signal for RVD in rat cultured cerebellar astrocytes. 相似文献
17.
Jingli Yang Yucheng Wang Guifeng Liu Chuanping Yang Chenghao Li 《Molecular biology reports》2011,38(3):1567-1574
A metallothionein-like gene, ThMT3, encoding a type 3 metallothionein, was isolated from a Tamarix hispida leaf cDNA library. Expression analysis revealed that mRNA of ThMT3 was upregulated by high salinity as well as by heavy metal ions, and that ThMT3 was predominantly expressed in the leaf. Transgenic yeast (Saccharomyces cerevisiae) expressing ThMT3 showed increased tolerance to Cd2+, Zn2+, Cu2+, and NaCl stress. Transgenic yeast also accumulated more Cd2+, Zn2+, and NaCl, but not Cu2+. Analysis of the expression of four genes (GLR1, GTT2, GSH1, and YCF1) that aid in transporting heavy metal (Cd2+) from the cytoplasm to the vacuole demonstrated that none of these genes were induced under Cd2+, Zn2+, Cu2+, and NaCl stress in ThMT3-transgenic yeast. H2O2 levels in transgenic yeast under such stress conditions were less than half those in control yeast under the same conditions.
Three antioxidant genes (SOD1, CAT1, and GPX1) were specifically expressed under Cd2+, Zn2+, Cu2+, and NaCl stress in the transgenic yeast. Cd2+, Zn2+, and Cu2+ increased the expression levels of SOD1, CAT1, and GPX1, respectively, whereas NaCl induced the expression of SOD1 and GPX1. 相似文献
18.
Cooke PS Holsberger DR Cimafranca MA Meling DD Beals CM Nakayama K Nakayama KI Kiyokawa H 《Obesity (Silver Spring, Md.)》2007,15(6):1400-1408
Objective: The etiology of some obesity may involve adipocyte hyperplasia. However, the role of adipocyte number in establishing adipose mass is unclear. Cyclin‐dependent kinase inhibitor p27 regulates activity of cyclin/cyclin‐dependent kinase complexes responsible for cell cycle progression. This protein is critical for establishing adult adipocyte number, and p27 knockout increases adult adipocyte number. The SCF (for Skp1‐Cullin‐F‐box protein) complex targets proteins such as p27 for ubiquitin‐proteosome degradation; the F box protein S phase kinase‐associated protein 2 (Skp2), a component of the SCF complex, specifically recognizes p27 for degradation. We used Skp2 knockout (Skp2?/?) mice to test whether Skp2 loss decreased adipose mass and adipocyte number. Research Methods and Procedures: We measured body weight, adipose mass, adipocyte diameter and number, and glucose tolerance in wild‐type (WT), Skp2?/?, and p27?/?Skp2?/? mice. Mouse embryo fibroblasts (MEFs) from WT and Skp2?/? fetuses were differentiated to determine whether Skp2 directly affected adipogenesis. Results: Skp2?/? mice had a 50% decrease in both subcutaneous and visceral fat pad mass and adipocyte number; these decreases exceeded those in body weight, kidney, or muscle. To test the hypothesis that Skp2 effects on adipocyte number involved p27 accumulation, we used p27?/?Skp2?/? double knockout mice. The Skp2?/? decrements in adipocyte number and fat pad mass were totally reversed in p27?/?Skp2?/? mice. Adipogenesis was inhibited in MEFs from Skp2?/? vs. WT mice, and this inhibition was absent in MEFs from p27?/?Skp2?/? mice. Discussion: Our results indicate that Skp2 regulates adipogenesis and ultimate adipocyte number in vivo; thus, Skp2 may contribute to obesity involving adipocyte hyperplasia. 相似文献
19.
John D. Tyler William J. Burlingham Chella S. David David Steinmuller 《Immunogenetics》1982,16(1):23-36
Mice of the C3H/He and A non-H-2 backgrounds are disparate from mice of the B10 background for the tissue-restricted, non-H-2 alloantigen of epidermal cells (EC), Epa-1, that is expressed by EC but not by lymphocytes (LC), as well as for a number of other alloantigens of the B10 background that are expressed by both EC and LC, generically referred to as lymphocyte/epidermal alloantigens (LEA). In this study, we compared the ability of various H-2 congenic strains on the C3H or A backgrounds to mount cytotoxic T-lymphocyte (CTL) responses to EC from H-2 compatible mice of the B10 background. High responses to Epa-1 were detected only in the H-2
aand H-2
khaplotypes; H-2
b, H-2
o1, H-2
s, H-2
t1, and H-2
t2 haplotypes were nonresponders to Epa-1. High responses to LEA were detected in H-2
a, H-2
b, H-2
s, H-2
t1, and H-2
t2 haplotypes; H-2
kand H-2
o1 were nonresponsive to LEA. Analysis of the H-2K, I and D region alleles of responders indicates that H-2K
kis essential for anti-Epa CTL responses, whereas D
d, D
b, or K
swere all permissive for strong anti-LEA responses. The ability to mount a given CTL response was not associated with differences in I-region alleles. These results are discussed in terms of K/D region products serving as Ir-gene products for CTL and in determining the apparent tissue-specificity of CTL. 相似文献
20.
Patience M. Burt Liping Xiao Thomas Doetschman Marja M. Hurley 《Journal of cellular physiology》2019,234(4):4418-4431
FGF2 is an essential growth factor implicated in osteoarthritis (OA), and deletion of full-length FGF2 (Fgf2ALLKO) leads to murine OA. However, the FGF2 gene encodes both high-molecular-weight (HMW) and low-molecular-weight (LMW) isoforms, and the effects of selectively ablating individual isoforms, as opposed to total FGF2, has not been investigated in the context of OA. We undertook this study to examine whether mice lacking HMW FGF2 (Fgf2HMWKO) or LMW FGF2 (Fgf2LMWKO) develop OA and to further characterize the observed OA phenotype in Fgf2ALLKO mice. Fgf2HMWKO mice never developed OA, but 6- and 9-month-old Fgf2LMWKO and Fgf2ALLKO mice displayed signs of OA, including eroded articular cartilage, altered subchondral bone and trabecular architecture, and increased OA marker enzyme levels. Even with mechanical induction of OA, Fgf2HMWKO mice were protected against OA, whereas Fgf2LMWKO and Fgf2ALLKO displayed OA-like changes of the subchondral bone. Before exhibiting OA symptoms, Fgf2LMWKO or Fgf2ALLKO joints displayed differential expression of genes encoding key regulatory proteins, including interleukin-1β, insulin-like growth factor 1, bone morphogenetic protein 4, hypoxia-inducible factor 1, B-cell lymphoma 2, Bcl2-associated X protein, a disintegrin and metalloproteinase with thrombospondin motifs 5, ETS domain-containing protein, and sex-determining region Y box 9. Moreover, Fgf2LMWKO OA cartilage exhibited increased FGF2, FGF23, and FGFR1 expression, whereas Fgf2HMWKO cartilage had increased levels of FGFR3, which promotes anabolism in cartilage. These results demonstrate that loss of LMW FGF2 results in catabolic activity in joint cartilage, whereas absence of HMW FGF2 with only the presence of LMW FGF2 offers protection from OA. 相似文献