Adhesion of pollen grains to the stigmatic surface is a critical step during sexual reproduction in plants. In Brassica, S locus-related glycoprotein 1 (SLR1), a stigma-specific protein belonging to the S gene family of proteins, has been shown to be involved in this step. However, the identity of the interacting counterpart in pollen and the molecular mechanism of this interaction have not been determined. Using an optical biosensor immobilized with S gene family proteins, we detected strong SLR1-binding activity in pollen coat extracts of Brassica campestris. Two SLR1-binding proteins, named SLR1-BP1 and SLR1-BP2, were identified and purified by the combination of SLR1 affinity column chromatography and reversephase HPLC. Sequence analyses revealed that these two proteins (i) differ only in that a proline residue near the N terminus is hydroxylated in SLR1-BP1 but not in SLR1-BP2, and (ii) are members of the class A pollen coat protein (PCP) family, which includes PCP-A1, an SLG (S locus glycoprotein)-binding protein isolated from Brassica oleracea. Kinetic analysis showed that SLR1-BP1 and SLR1-BP2 specifically bound SLR1 with high affinity (Kd ؍ 5.6 and 4.4 nM, respectively). The SLR1-BP gene was specifically expressed in pollen at late stages of development, and its sequence is highly conserved in Brassica species with the A genome. Sexual reproduction in plants depends on highly specific interactions between pollen and the pistil. These interactions are the basis of interspecific and intraspecific recognition systems, which allow the pistil to distinguish among genetically diverse ranges of pollen grains arriving at the stigma. Germination and growth of ''appropriate'' pollen grains are selectively promoted, whereas ''inappropriate'' pollen grains are selectively inhibited. One notable example of an intraspecific recognition system is self-incompatibility (SI) (1).In Brassica, SI is controlled by a single polymorphic locus, termed the S locus. Two stigmatically expressed polymorphic genes have been identified at the S locus. One is the S locus glycoprotein (SLG) gene, which encodes a secreted glycoprotein (2, 3), and the other is the S locus receptor kinase (SRK) gene, which encodes a receptor-like serine͞threonine protein kinase (4). SRK is the sole determinant of the S haplotype specificity of the stigma (5); its extracellular domain, which is highly similar to SLG, is thought to interact with the pollen S determinant of the same S haplotype. Recently, the gene encoding the pollen S determinant has been identified (6-8). This gene, designated SP11 (S locus protein 11) or SCR (S locus cysteine-rich), encodes a novel class within a family of proteins named the pollen coat protein (PCP) family (9, 10). It is hypothesized that interactions between SP11͞SCR and SRK elicit a signaling cascade within the surface cells of the stigma, the papillae, leading to the rejection of self-pollen. The role of SLG in SI is enhancing the recognition process between the stigma and self-pollen (5).The Brassica genome contai...
for the GENCAT Study Group IMPORTANCE Carbamazepine, a commonly used antiepileptic drug, is one of the most common causes of cutaneous adverse drug reactions (cADRs) worldwide. The allele HLA-A*31:01 is reportedly associated with carbamazepine-induced cADRs in Japanese and European populations; however, the clinical utility of HLA-A*31:01 has not been evaluated.OBJECTIVE To assess the use of HLA-A*31:01 genetic screening to identify Japanese individuals at risk of carbamazepine-induced cADRs.DESIGN, SETTING, AND PARTICIPANTS This cohort study was conducted across 36 hospitals in Japan from January 2012 to November 2014 among 1202 patients who had been deemed suitable to start treatment with carbamazepine. Preemptive HLA-A*31:01 genetic screening was performed for 1187 participants. Patients who did not start treatment with carbamazepine or alternative drugs were excluded. Participants were interviewed once weekly for 8 weeks to monitor the development of cADRs. Data analysis was performed from June 8, 2015, to December 27, 2016.EXPOSURES Neuropsychiatrists were asked to prescribe carbamazepine for patients who tested negative for HLA-A*31:01 and alternative drugs for those who tested positive for HLA-A*31:01. MAIN OUTCOMES AND MEASURES Incidence of carbamazepine-induced cADRs.RESULTS Of the 1130 included patients who were prescribed carbamazepine or alternative drugs, the mean (range) age was 37.4 (0-95) years, 614 (54.3%) were men, and 198 (17.5%) were positive for HLA-A*31:01. Expert dermatologists identified 23 patients (2.0%) who had carbamazepine-induced cADRs, of which 4 patients required hospitalization. Drug-induced hypersensitivity syndrome was observed for 3 patients, maculopapular eruption for 9 patients, erythema multiforme for 5 patients, and an undetermined type of cADR for 6 patients. No patient developed Stevens-Johnson syndrome or toxic epidermal necrolysis. Compared with historical controls, the incidence of carbamazepine-induced cADRs was significantly decreased (for BioBank Japan data: incidence, 3.4%; odds ratio, 0.60; 95% CI, 0.36-1.00; P = .048; for the Japan Medical Data Centre claims database: incidence, 5.1%; odds ratio, 0.39; 95% CI, 0.26-0.59; P < .001).CONCLUSIONS AND RELEVANCE Preemptive HLA-A*31:01 genetic screening significantly decreased the incidence of carbamazepine-induced cADRs among Japanese patients, which suggests that it may be warranted in routine clinical practice.
We examined four type 1 polioviruses isolated from the stools of patients with vaccine-associated paralytic poliomyelitis in China. All of these isolates were shown to be Sabin derived viruses by restriction fragment length polymorphism assay after polymerase chain reaction and by sequencing of the viral genome encoding the viral coat protein, VP1. However, the same analysis of the 3D coding region suggested that two of the four isolates had the sequence of wild type poliovirus in the tested region. Furthermore there were also point mutations in the 5' non-coding region. One was a single base change from U to C at nucleotide position 525, and the other three were from G to A at position 480. All the four strains were more neurovirulent that Sabin type 1 virus in transgenic mice with human poliovirus receptor gene. The data showed that the nucleotide positions of type 1 poliovirus which were identified to be in favor of the high neurovirulence were indeed changed during natural transmission, and suggested that the point mutation alone or a recombination of the vaccine type with wild type genome results in an acquisition of neurovirulence.
A 3-year-old boy with agammaglobulinemia developed paralytic poliomyelitis on day 553 after being fed poliovaccine. Non-vaccine-like type 2' polioviruses were isolated from 22 stools obtained within 684 days after the onset of illness. Antigenic variations were observed among these viruses. The nonvaccine-like virus isolated 1 week after the onset of paralysis differed in virulence from the Sabin type 2 vaccine strain in the neurovirulence test in monkeys, and did not have the same antigenic character as the wild virulent strains. Another virus isolated on day 348 before the onset of illness was also classified as non-vaccine-like. However, the Sabin type 2 strain was shown to be homologous with this strain by the McBride test. Some Sabin-like particles were found in this stock virus. We may conclude that the non-vaccine-like virus isolates were derived from Sabin vaccine by antigenic variation that occurred during long-term multiplication in the intestinal tract.
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