HLA-B*51 allele analysis by the PCR-SBT method and a strong association of HLA-B*5101 with Japanese patients with Behçet's disease

Behçet's disease (BD) is known to be associated with human leukocyte antigen (HLA) B51 in many different ethnic groups. An increased incidence of HLA-B51 in the patient group has also been reported in a Japanese population. Recently, the B51 antigen has been identified to comprise 21 alleles, B*5101-B*5121. Further, not only HLA-B*5101 but also HLA-B*5108 were found to be relatively increased in the patient groups among Italian and Saudi Arabian populations. Therefore, we performed HLA-B*51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method in order to investigate whether there is any correlation of one particular B51-associated allele with Japanese BD. Ninety-six Japanese patients with BD and 132 healthy Japanese volunteers were enrolled in this study. As a result, the phenotype frequency of the B51 antigen was confirmed to be remarkably increased in the patient group as compared to the ethnically matched control group (59.4% in patients vs. 13.6% in controls; Pc=0.0000000000098, R.R.=9.3). In the B*51 allele genotyping, 56 out of 57 B51-positive patients were defined as B*5101 and the remaining one was B*5102. In contrast, all of 18 B51-positive normal controls were B*5101. None of the Japanese patients and healthy controls carried the HLA-B*5108 allele. This study revealed that B*51 allelic distribution in Japanese was different from those in Italian and Saudi Arabian populations, and that the significantly high incidence of the HLA-B51 antigen in the Japanese BD patient group was mostly caused by the significant increase of the HLA-B*5101 allele.

Clathrin box in G protein-coupled receptor kinase 2

beta(1)-Adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. However, beta(1)AR can internalize as G protein-coupled receptor kinase 2 (GRK2) is fused to its carboxyl terminus. Internalization of the beta(1)AR and GRK2 fusion protein (beta(1)AR/GRK2) is dependent on dynamin but independent of beta-arrestin and phosphorylation. The beta(1)AR/GRK2 fusion protein internalizes via clathrin-coated pits and is found to co-localize with the endosome that contains transferrin. The fusion proteins consisting of beta(1)AR and various portions of GRK2 reveal that the residues 498-502 in the carboxyl-terminal domain of GRK2 are critical to promote internalization of the fusion proteins. This domain contains a consensus sequence of a clathrin-binding motif defined as a clathrin box. In vitro binding assays show that the residues 498-502 of GRK2 bind the amino-terminal domain of clathrin heavy chain to almost the same extent as beta-arrestin1. The mutation of the clathrin box in the carboxyl-terminal domain of GRK2 results in the loss of the ability to promote internalization of the fusion protein. GRK2 activity increases and then decreases as the concentration of clathrin heavy chain increases. Taken together, these results imply that GRK2 contains a functional clathrin box and directly interacts with clathrin to modulate its function.

The absence of disease-specific polymorphisms within the HLA-B51 gene that is the susceptible locus for Behçet's disease

Behçet's disease is known to be associated with HLA-B51 in many different populations. Genetic evidence supports that the susceptible gene for Behçet's disease is the HLA-B51 allele at the HLA-B locus. This study was aimed to determine the HLA-B51 nucleotide sequence variation in three Behçet's disease patients and three healthy controls in order to elucidate if any disease specific mutations or polymorphisms may exist in the HLA-B51 gene of patients. Long-range polymerase chain reaction (PCR) was first carried out to give a PCR-amplified product of 9.5 kb which was then used as a template for nested PCR to give a final amplified product of 4.2 kb. This final product containing the 1.3-kb promoter/enhancer region and the entire HLA-B gene except for a 363-bp 3' terminal end segment encoding the 3' untranslated region was subcloned by the BP cloning technique and sequenced. The sequencing results showed that all the patients possessed the HLA-B*51011 allele, and there were no differences in the exonic nucleotide sequences between the three Behçet's disease patients and the three healthy controls. The HLA-B*51011 intronic and promoter/enhancer nucleotide sequences from the three patients had 22 single nucleotide polymorphisms (SNPs), a single insertion of 6 bp and a single deletion of 2 bp. On the other hand, the three healthy controls had 24 SNPs in their intronic and promoter/enhancer regions. However, none of these polymorphisms in the patients were specific for the disease. Therefore, these results clearly demonstrate that the HLA-B exonic sequence that encodes the HLA-B51 allele is the real pathogenic factor in Behçet's disease.

The association between HLA-A alleles and an Alu dimorphism near HLA-G

The AluYb8 sequences are a subfamily of short interspersed Alu retroelements that have been amplified within the human genome during recent evolutionary time and are useful polymorphic markers for studies on the origin of human populations. We have identified a new member of the Yb8 subfamily, AluyHG, located between the HLA-H and -G genes and 88-kb telomeric of the highly polymorphic HLA-A gene within the alpha block of the major histocompatibility complex (MHC). The AluyHG element was characterised with a view to examining the association between AluyHG and HLA-A polymorphism and reconstructing the history of the MHC alpha block. A specific primer pair was designed for a simple PCR assay to detect the absence or presence (dimorphism) of the AluyHG element within the DNA samples prepared from a panel of 46 homozygous cell-lines containing complete or recombinant ancestral haplotypes (AH) of diverse ethnic origin and 92 Caucasoid and Asian subjects on which HLA-A typing was available. The AluyHG insertion was most strongly associated with HLA-A2 and, to a lesser degree with HLA-A1, -A3, -A11, and A-19. The gene frequency of the AluyHG insertion for 146 Caucasians and 94 Chinese-Han was 0.30 and 0.32 and there was no significant difference between the observed and expected frequencies. The results of the association studies and the phylogenetic analysis of HLA-A alleles suggest that the AluyHG sequence was integrated within the progenitor of HLA-A2, but has been transferred by recombination to other human ancestral populations. In this regard, the dimorphic AluyHG element is an important diagnostic marker for HLA association studies and could help in elucidating the evolution and functions of the MHC alpha block and polymorphism within and between ancestral haplotypes.

Measurement of the midrapidity transverse energy distribution from square root of [(s)NN] = 130 GeV Au + Au collisions at RHIC

The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that <E(T)>/<N(ch)> remains relatively constant as a function of centrality. The energy density calculated via Bjorken's prescription for the 2% most central Au+Au collisions at square root[s(NN)] = 130 GeV is at least epsilon(Bj) = 4.6 GeV/fm(3), which is a factor of 1.6 larger than found at sqrt[s(NN)] = 17.2 GeV ( Pb+Pb at CERN).

Songbird genomics: analysis of 45 kb upstream of a polymorphic Mhc class II gene in red-winged blackbirds (Agelaius phoeniceus)

Here we present the sequence of a 45 kb cosmid containing a previously characterized poly-morphic Mhc class II B gene (Agph-DAB1) from the red-winged blackbird (Agelaius phoeniceus). We compared it with a previously sequenced cosmid from this species, revealing two regions of 7.5 kb and 13.0 kb that averaged greater than 97% similarity to each another, indicating a very recent shared duplication. We found 12 retroelements, including two chicken repeat 1 (CR1) elements, constituting 6.4% of the sequence and indicating a lower frequency of retroelements than that found in mammalian genomic DNA. Agph-DAB3, a new class II B gene discovered in the cosmid, showed a low rate of polymorphism and may be functional. In addition, we found a Mhc class II B gene fragment and three genes likely to be functional (encoding activin receptor type II, a zinc finger, and a putative gamma-filamin). Phylogenetic analysis of exon 2 alleles of all three known blackbird Mhc genes indicated strong clustering of alleles by locus, implying that large amounts of interlocus gene conversion have not occurred since these genes have been diverging. Despite this, interspecific comparisons indicate that all three blackbird Mhc genes diverged from one another less than 35 million years ago and are subject to concerted evolution in the long term. Comparison of blackbird and chicken Mhc promoter regions revealed songbird promoter elements for the first time. The high gene density of this cosmid confirms similar findings for the chicken Mhc, but the segment duplications and diversity of retroelements resembles mammalian sequences.

Genetic variations and polymorphisms of G protein-coupled receptors: functional and therapeutic implications

G protein-coupled receptors (GPCRs) represent a major class of proteins in the genome of many species, including humans. In addition to the mapping of a number of human disorders to regions of the genome containing GPCRs, a growing body of literature has documented frequently occurring variations (i.e. polymorphisms) in GPCR loci. In this article, we use a domain-based approach to systematically examine examples of genetic variation in the coding and noncoding regions of GPCR loci. Data to date indicate that residues in GPCRs are involved in ligand binding and coupling to G proteins and that regulation can be altered by polymorphisms. Studies of GPCR polymorphisms have also uncovered the functional importance of residues not previously implicated from other approaches that are involved in the function of GPCRs. We predict that studies of GPCR polymorphisms will have a significant impact on medicine and pharmacology, in particular, by providing new means to subclassify patients in terms of both diagnosis and treatment.

Low affinity of beta1-adrenergic receptor for beta-arrestins explains the resistance to agonist-induced internalization

It has been reported that beta-arrestin is essential for the internalization of many G protein-coupled receptors. Since beta1-adrenergic receptor (beta1AR) shows the resistance to agonist-induced internalization, we examine the interaction of beta-arrestin with beta1AR with three different approaches: translocation of beta-arrestin to the plasma membrane, direct binding of in vitro translated beta-arrestin to intracellular domains of beta1- and beta2ARs, inhibition of beta1- and beta2AR-stimulated adenylyl cyclase activities by beta-arrestin. The enhanced green fluorescent protein (EGFP)-tagged beta-arrestin 2 (beta-arrestin 2-GFP) translocates to and stays at the plasma membrane by beta2AR stimulation. Beta-arrestin 2-GFP also translocates to the plasma membrane upon beta1AR stimulation. However, it returns to the cytoplasm 10 - 30 min after agonist stimulation. The amount of beta-arrestin bound to the third intracellular loop and the carboxyl tail of beta1AR is lower than that of beta2AR. The fusion protein of beta-arrestin 1 with glutathione-S-transferase inhibits the beta1- and beta2AR-stimulated adenylyl cyclase activities. However, inhibition of the beta1AR-stimulated activity requires a higher amount of the fusion protein than that of the beta2AR-stimulated activity. These results suggest that affinity of beta1AR for beta-arrestins is lower than that of beta2AR, and explains the resistance to agonist-induced internalization. This conclusion is further supported by the finding that beta-arrestin can induce internalization of beta1AR when beta-arrestin 1 fused to the carboxyl tail of beta1AR.

Centrality dependence of charged particle multiplicity in Au-Au collisions at square root of (s)NN = 130 GeV

We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at square root of [s(NN)] = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta(vertical line eta = 0) = 622+/-1(stat)+/-41(syst). The results, analyzed as a function of centrality, show a steady rise of the particle density per participating nucleon with centrality.

Characterization and developmental expression of the amphioxus homolog of Notch (AmphiNotch): evolutionary conservation of multiple expression domains in amphioxus and vertebrates

Notch encodes a transmembrane protein that functions in intercellular signaling. Although there is one Notch gene in Drosophila, vertebrates have three or more with overlapping patterns of embryonic expression. We cloned the entire 7575-bp coding region of an amphioxus Notch gene (AmphiNotch), encoding 2524 amino acids, and obtained the exon/intron organization from a genomic cosmid clone. Southern blot and PCR data indicate that AmphiNotch is the only Notch gene in amphioxus. AmphiNotch, like Drosophila Notch and vertebrate Notch1 and Notch2, has 36 EGF repeats, 3 Notch/lin-12 repeats, a transmembrane region, and 6 ankyrin repeats. Phylogenetic analysis places it at the base of all the vertebrate genes, suggesting it is similar to the ancestral gene from which the vertebrate Notch family genes evolved. AmphiNotch is expressed in all three embryonic germ layers in spatiotemporal patterns strikingly similar to those of all the vertebrate homologs combined. In the developing nerve cord, AmphiNotch is first expressed in the posteriormost part of the neural plate, then it becomes more broadly expressed and later is localized dorsally in the anteriormost part of the nerve cord corresponding to the diencephalon. In late embryos and larvae, AmphiNotch is also expressed in parts of the pharyngeal endoderm, in the anterior gut diverticulum, and, like AmphiPax2/5/8, in the rudiment of Hatschek's kidney. A comparison with Notch1 and Pax5 and Pax8 expression in the embryonic mouse kidney helps support homology of the amphioxus and vertebrate kidneys. AmphiNotch is also an early marker for presumptive mesoderm, transcripts first being detectable at the gastrula stage in a ring of mesendoderm just inside the blastopore and subsequently in the posterior mesoderm, notochord, and somites. As in sea urchins and vertebrates, these domains of AmphiNotch expression overlap with those of several Wnt genes and brachyury. These relationships suggest that amphioxus shares with other deuterostomes a common mechanism for patterning along the anterior/posterior axis involving a posterior signaling center in which the Notch and Wnt pathways and brachyury interact.

cDNA cloning and genetic polymorphism of the swine major histocompatibility complex (SLA) class II DMA gene

cDNA clones corresponding to the swine histocompatibility complex (SLA: swine leucocyte antigen)-DM alpha chain were isolated using the polymerase chain reaction (PCR) products from the third exon in the human HLA-DMA gene as a probe. Amino acid comparative analysis revealed that these clones were more closely related to the bovine and human DMA genes than to the other swine class II genes alpha chain genes, DRA, DQA and DOA. These results suggest that the SLA-DMA gene is expressed and may function, like HLA-DM, as an important modulator in class II restricted antigen processing in swine. Furthermore, based on the sequences and PCR-restriction fragment length polymorphism (PCR-RFLP) patterns in the SLA-DMA gene, no allelic variation was recognized in the second exon, but five allelic variations were recognized in the third exon in five different breeds of swine. These DMA alleles were defined by variation at four nucleotide positions. Two of these alleles resulted in an amino acid substitution. These results suggest that SLA-DMA has little polymorphism as observed in HLA-DMA and mouse H2-Ma.

[Assessment of the new TNM classification for resected lung cancer]

To evaluate the revised TNM classification, we investigated the prognoses of 552 consecutive patients who had resection of non-small-cell lung cancer between April 1982 and March 1996. According to the new classification, the 5-year survival rate was 76.9% for stage I A, 57.2% for stage I B (I A versus I B, p < 0.0005), 47.7% for stage IIA, 49.8% for stage IIB, 18.6% for stage IIIA (IIB versus IIIA, p = 0.005), 16.7% for stage IIIB, and 7.9% for stage IV (IIIB versus IV, p = 0.02). Especially for patients in stage I A, there was significant difference in survival between patients with the tumor size within 1.5 cm and those with larger than 1.5 cm. The survival rate for T3N0M0 patients was significantly better than that for T3N1-2M0, but there was no significant difference between patients with T3N0M0 disease and those with T2N1M0 disease. Concerning the pm1 patients, the survival rate was significantly better than other stage IIIB patients. Our results supported the revision for dividing stage I and putting T3N0M0 into stage IIB. However, the classification is controversial about dividing stage II and putting pm1 as T4 disease. Furthermore, subgrouping of T1N0M0 disease by tumor size, T3 by tumor invaded organ will be necessary in the next revisions.

Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors

The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

Gene structure and promoter for Crad2 encoding mouse cis-retinol/3alpha-hydroxysterol short-chain dehydrogenase isozyme

Cis-retinol/androgen dehydrogenase type 2 (CRAD2) has been shown to catalyze the dehydrogenation of retinols, including 9-cis retinol, and also to exhibit 3alpha- and 17beta- hydroxysteroid dehydrogenase activities. To examine the function of this enzyme and regulation of its gene, the Crad2 gene was cloned from a mouse genomic DNA library and characterized. The complete mouse CRAD2-coding region was found in four exons spanning an approximately 5kb region. The nucleotide sequences of the exons encoding 316 amino acids were identical to those of the previously reported mouse Crad2 cDNA. Primer extension analysis and RNase protection assay were used to map the major transcription initiation sites to the positions lying 87 and 89 base pairs upstream of the ATG translation start codon. The region proximal to the initiation sites exhibited the absence of both TATAA and CAAT boxes. This region had hepatocyte nuclear factor binding sites, consistent with its predominant expression in the liver. Computer analysis of an approximately 7.5kb 5'-flanking region also suggested the presence of binding sites for AP-1, SREBP1, HSF2, c-Rel, c-Myc, CREBP, GATA, Ets, E2F, and Oct-1, suggesting that various factors including retinoic acid, cholesterol, various kinds of stress, the cell cycle, and cyclic AMP may regulate the expression of this gene. Fluorescence in-situ hybridization analysis showed that Crad2 is located at the terminus of mouse chromosome 10, an area that corresponds to band 10D3, suggesting that RDH-related SDRs may be located together in the cluster locus. Northern blot hybridization and RT-PCR analysis demonstrated that CRAD2 was expressed not in early embryonic stages, and not in embryonic stem cells, but instead in the gastrointestinal tract during later embryonic development and adult stage. In conclusion, we have presented the first complete structural analysis, including that of the promoter and chromosomal location, of a member of the retinol/androgen dehydrogenase subfamily of the group of the short-chain dehydrogenase/reductase (SDR) isozymes. Our findings will provide the basis for in-vitro or in-vivo studies concerning the regulation of retinol and androgen metabolism and enable determination of the mechanism of diseases related to retinol, retinal, retinoic acid, and androgen.

Chloroplast tubules visualized in transplastomic plants expressing green fluorescent protein

A fusion between the plastid psbA promoter and the green fluorescent protein gene (gfp) was introduced into the tobacco chloroplast genome by stable plastid transformation. GFP was synthesized actively and exclusively in the chloroplasts. Tubular projections filled with GFP but containing no chlorophyll were visualized for the first time in chloroplasts of these transplastomic plants. Occasionally, the tubules connect chloroplasts with each other, suggesting the possibility of the exchange of endogenous proteins. However, the fusion of protoplasts between the transplastomic and wild-type plants showed that such chloroplast connections might be rare in mesophyll protoplasts.

Genetic polymorphisms in the cell growth regulated gene, SC1 telomeric of the HLA-C gene and lack of association of psoriasis vulgaris

Psoriasis vulgaris is associated with the HLA-Cw6 and Cw7 antigens. We have previously narrowed down the critical region most likely to contain the psoriasis vulgaris gene to 111 kb spanning 89 kb to 200 kb telomeric of the HLA-C locus by microsatellite mapping. This segment includes three known genes (POU5F1, SC1 and S) and four new expressed genes. Among them, SC1 (TCF19) is the cell growth regulated gene possibly with trans-activator activity. Since psoriasis vulgaris is a common skin disorder characterized by hyperproliferation of epidermal cells, it is tempting to speculate that the SCI gene is one of the strong candidate genes responsible for the development of psoriasis vulgaris. Here, we investigated genetic polymorphisms in the SC1 gene by direct DNA sequencing and polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) techniques. Three single nucleotide polymorphisms in exon 2, two of which are accompanied by amino-acid substitutions, were identified. Further, one 4-bp deletion polymorphism was detected around the acceptor site of the lariat-shaped structure necessary for RNA splicing in intron 2. No significant difference in the dimorphic or haplotypic distribution at these four polymorphic sites was observed between the patients with psoriasis vulgaris and healthy controls. This suggests that the susceptible gene for psoriasis vulgaris is not the SC1 gene itself, although a unique homozygous haplotype was identified in the patients.

Detection of characteristic waves of sleep EEG by neural network analysis

In psychiatry, the sleep stage is one of the most important evidence for diagnosing mental disease. However, doctors require much labor and skill for diagnosis, so a quantitative and objective method is required for more accurate diagnosis since it depends on the doctor's experience. For this reason, an automatic diagnosis system must be developed. In this paper, we propose a new type of neural network (NN) model referred to as a sleep electroencephalogram (EEG) recognition neural network (SRNN) which enables us to detect several kinds of important characteristic waves in sleep EEG which are necessary for diagnosing sleep stages. Experimental results indicate that the proposed NN model was much more capable than other conventional methods for detecting characteristic waves.

Molecular dynamics of MHC genesis unraveled by sequence analysis of the 1,796,938-bp HLA class I region

The intensely studied MHC has become the paradigm for understanding the architectural evolution of vertebrate multigene families. The 4-Mb human MHC (also known as the HLA complex) encodes genes critically involved in the immune response, graft rejection, and disease susceptibility. Here we report the continuous 1,796,938-bp genomic sequence of the HLA class I region, linking genes between MICB and HLA-F. A total of 127 genes or potentially coding sequences were recognized within the analyzed sequence, establishing a high gene density of one per every 14.1 kb. The identification of 758 microsatellite provides tools for high-resolution mapping of HLA class I-associated disease genes. Most importantly, we establish that the repeated duplication and subsequent diversification of a minimal building block, MIC-HCGIX-3.8-1-P5-HCGIV-HLA class I-HCGII, engendered the present-day MHC. That the currently nonessential HLA-F and MICE genes have acted as progenitors to today's immune-competent HLA-ABC and MICA/B genes provides experimental evidence for evolution by "birth and death," which has general relevance to our understanding of the evolutionary forces driving vertebrate multigene families.

Kimura's disease with bilateral auricular masses

We report an unusual case of Kimura's disease. An 81-year-old Japanese woman was shown to have bilateral auricular masses that had begun to enlarge 6 years before. On CT scans, slightly high-density masses with faint contrast enhancement were seen. The masses were heterogeneous and hypointense on T1-weighted MR images, were slightly hyperintense on T2-weighted MR images, and showed heterogeneous enhancement after the administration of contrast material. Kimura's disease should be included in the differential diagnosis of bilateral auricular tumors.

Association analysis using refined microsatellite markers localizes a susceptibility locus for psoriasis vulgaris within a 111 kb segment telomeric to the HLA-C gene

The HLA-Cw6 antigen has been associated with psoriasis vulgaris despite racial and ethnic differences. However, it remains unclear whether it is the HLA-Cw6 antigen itself or a closely linked, hitherto unidentified, locus that predisposes to the disease. Here, in order to map the susceptibility locus for psoriasis vulgaris precisely within the HLA class I region, 11 polymorphic microsatellite markers distributed throughout a 1060 kb segment surrounding the HLA-C locus were subjected to association analysis in Japanese psoriasis vulgaris patients. Statistical analyses of the distribution and deviation from Hardy-Weinberg equilibrium of the allelic frequency at each micro-satellite locus revealed that the pathogenic gene for psoriasis vulgaris is located within a reduced interval of 111 kb spanning 89-200 kb telomeric of the HLA-C gene. In addition to three known genes, POU5F1, TCF19 and S, this 111 kb fragment contains four new, expressed genes identified in the course of our genomic sequencing of the entire HLA class I region. Therefore, these seven genes are the potential candidates for susceptibility to psoriasis vulgaris.

New polymorphic microsatellite markers in the human MHC class I region

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of genes encoding susceptible factors for diseases such as Behcet's disease, Graves disease and psoriasis vulgaris. To identify the causative genes of those diseases, we have conducted large-scale genomic sequencing and determined the 1.8 Mb entire HLA class I region from the MICB gene to the HLA-F gene. During the course of genomic sequencing, a total of 731 microsatellite sequences with dinucleotide to pentanucleotide repeats were found in this region. Previously, we reported that 26 microsatellites between MICB and S on the most centromeric side of the class I region, and between HSR1 and HLA-92/L in the midst of the class I region were highly polymorphic, and served as excellent genetic markers. In this paper, in order to fill the gaps with no known polymorphic microsatellites available in the HLA class I region, 12 new polymorphic microsatellite markers were recruited from the 1.8 Mb region including the remaining class I segments, namely between S and HSR1, and between HLA-92/L and HLA-F The average number of alleles at these new microsatellite loci was 8.2 with a polymorphism content value (PIC) of 0.63. These 38 markers in total almost uniformly interspersed in the HLA class I region will enable us to search precisely for the location of disease susceptible loci within the HLA class I region by association and for linkage analyses.

Species differences in the transport activity for organic anions across the bile canalicular membrane

Species differences in the transport activity mediated by canalicular multispecific organic anion transporter (cMOAT) were examined using temocaprilat, an angiotensin-converting enzyme inhibitor whose biliary excretion is mediated predominantly by cMOAT, and 2,4-dinitrophenyl-S-glutathione, a typical substrate for cMOAT, in a series of in vivo and in vitro experiments. Temocaprilat was infused to examine the biliary excretion rate at steady-state. The in vivo transport clearance values across the bile canalicular membrane, defined as the biliary excretion rate divided by the hepatic unbound concentrations, were 9.8, 39.2, 9.2, 1.1, and 0.8 ml/min/kg for mouse, rat, guinea pig, rabbit, and dog, respectively. The K(m) and V(max) values for ATP-dependent uptake of 2, 4-dinitrophenyl-S-glutathione into canalicular membrane vesicles were 15.0, 29.6, 16.1, 55.8, and 30.0 microM and 0.38, 1.90, 0.15, 0. 47, and 0.23 nmol/min/mg protein, yielding the in vitro transport clearance across the bile canalicular membrane (V(max)/K(m)) of 25.5, 64.2, 9.4, 8.4, and 7.7 for mouse, rat, guinea pig, rabbit, and dog, respectively. A close in vivo and in vitro correlation was observed among animal species for the transport clearance across the bile canalicular membrane. These results suggest that the uptake experiments with canalicular membrane vesicles can be used to quantitatively predict in vivo excretion across the bile canalicular membrane.

MIC-A polymorphism in Japanese and a MIC-A-MIC-B null haplotype

A polymorphic gene, MIC-A, is one of the MIC family of genes which is composed of a group of homologous genes interspersed in the class III and class I regions of the major histocompatibility complex. MIC-A is located 46 kilobases (kb) centromeric of HLA-B, and is preferentially expressed in the epithelial cells and intestinal mucosa. Recently, MIC-A and the closely related MIC-B were reported as the molecules that conferred specificity in the recognition by the Vdelta1gammadeltaT cells. In the present study, polymorphic exons 2, 3, and 4 of the MIC-A gene were analyzed using the polymerase chain reaction-single-strand conformation polymorphism method. The number of patterns found in exons 2, 3, and 4 were 5, 6, and 4, respectively, in 114 healthy Japanese subjects. Eight MIC-A alleles were observed in Japanese individuals, among which one, tentatively named MIC-AMW, has not previously been reported. There was a strong linkage disequilibrium between MIC-A and HLA-B loci: each MIC-A allele showed strong association with a particular HLA-B group. In contrast, B*3901 showed association with multiple MIC-A alleles. Furthermore, the existence of a MIC-A-MIC-B null haplotype, which is associated with HLA-B*4801, was identified. In this haplotype, a large-scale deletion (of approximately 100 kb) including the entire MIC-A gene was indicated and the MIC-B gene possessed a stop codon.

Alpha1,3-fucosyltransferase IX (Fuc-TIX) is very highly conserved between human and mouse; molecular cloning, characterization and tissue distribution of human Fuc-TIX

The amino acid sequence of Fuc-TIX is very highly conserved between mouse and human. The number of non-synonymous nucleotide substitutions of the Fuc-TIX gene between human and mouse was strikingly low, and almost equivalent to that of the alpha-actin gene. This indicates that Fuc-TIX is under a strong selective pressure of preservation during evolution. The human Fuc-TIX (hFuc-TIX) showed a unique characteristics, i.e. hFuc-TIX was not activated by Mn2+ and Co2+, whereas hFuc-TIV and hFuc-TVI were activated by the cations. The hFuc-TIX transcripts were abundantly expressed in brain and stomach, and interestingly were detected in spleen and peripheral blood leukocytes.

Circadian-regulated expression of a nuclear-encoded plastid sigma factor gene (sigA) in wheat seedlings

The activity of a light-responsive psbD promoter in plastids is known to be regulated by a circadian clock. However, the mechanism of the circadian regulation of the psbD light-responsive promotor, which is recognized by an Escherichia coli-type RNA polymerase, is not yet known. We examined the time course of mRNA accumulation of two E. coli-type RNA polymerase subunit genes, sigA and rpoA, under a continuous light condition after 12 h light/12 h dark entrainment. Accumulation of the sigA mRNA was found to be regulated by a circadian clock, while rpoA mRNA did not show any significant oscillation throughout the experiment.

Gene organization of the quail major histocompatibility complex (MhcCoja) class I gene region

Class I genomic clones of the quail (Coturnix japonica) major histocompatibility complex (MhcCoja) were isolated and characterized. Two clusters spanning the 90.8 kilobase (kb) and 78.2 kb class I gene regions were defined by overlapping cosmid clones and found to contain at least twelve class I loci. However, unlike in the chicken Mhc, no evidence for the existence of any Coja class II gene was obtained in these two clusters. Based on comparative analysis of the genomic sequences with those of the cDNA clones, Coja-A, Coja-B, Coja-C, and Coja-D (Shiina et al. 1999), these twelve loci were assigned to represent one Coja-A gene, two Coja-B genes (Coja-B1 and -B2), four Coja-C genes (Coja-C1-C4), four Coja-D genes (Coja-D1-D4), and one new Coja-E gene. A class I gene-rich segment of 24.6 kb in which five of these genes (Coja-B1, -B2, -D1, -D2 and -E) are densely packed were sequenced by the shotgun strategy. All of these five class I genes are very compact in size [2089 base pairs (bp)-2732 bp] and contain no apparent genetic defect for functional expression. A transporter associated with the antigen processing (TAP) gene was identified in this class I gene-rich segment. These results suggest that the quail class I region is physically separated from the class II region and characterized by a large number of the expressible class I loci (at least seven) in contrast to the chicken Mhc, where the class I and class II regions are not clearly differentiated and only at most three expressed class I loci so far have been recognized.

Developmental stage-specific multi-subunit plastid RNA polymerases (PEP) in wheat

Most photosystem I and II plastid genes are transcribed by a plastid encoded Escherichia coli-like RNA polymerase (PEP). In this study, we show that both promoter selectivity and light-dependency of PEP change dramatically during development in wheat leaves. In the leaf tip, psbA and psbD promoter activities are light induced, whilst psbC, psbE and 16S rRNA promoters do not function efficiently irrespective of light conditions. In contrast to the leaf tip, in the basal portion all PEP promoters studied function in the dark as well as the light, except for psbD. Using in vitro transcription, we found that PEP in the illuminated leaf tip can initiate transcription from the -35 destructed psbA promoter, but the -35 element is essential for transcription in the basal portion. There is an extended -10 element in the psbA promoter, recognized by the PEP in the illuminated leaf tip or purified sigma 70-type Escherichia coli RNA polymerase but not by the PEP in the leaf base. These results suggest that during wheat leaf development, PEP in the leaf base that is functional for most PEP promoters even in the dark is replaced by the light-dependent PEP selectively transcribing the psbA and psbD promoters.

The critical region for Behçet disease in the human major histocompatibility complex is reduced to a 46-kb segment centromeric of HLA-B, by association analysis using refined microsatellite mapping

The HLA-B51 allele is known to be associated with Behçet disease. Recently, we found a higher risk for Behçet disease in the MICA gene, 46 kb centromeric of HLA-B, by investigation of GCT repetitive polymorphism within exon 5 of MICA. The pathogenic gene causing Behçet disease, however, has remained uncertain. Here, eight polymorphic microsatellite markers, distributed over a 900-kb region surrounding the HLA-B locus, were subjected to association analysis for Behçet disease. Statistical studies of associated alleles detected on each microsatellite locus showed that the pathogenic gene for Behçet disease is most likely found within a 46-kb segment between the MICA and HLA-B genes. The results of this mapping study, and the results of an earlier study of ours, suggest that MICA is a strong candidate gene for the development of Behçet disease.

Geranylgeranylpyrophosphate plays a key role for the G1 to S transition in vascular smooth muscle cells

Pravastatin, a HMG-CoA reductase inhibitor was found to inhibit DNA synthesis of vascular smooth muscle cells (VSMC) in a dose-dependent manner. Flow cytometric analysis demonstrated that pravastatin induced G1 arrest. Mevalonate restored the inhibitory effect of pravastatin on DNA synthesis and on cell cycle progression, suggesting the importance of mevalonate itself and/or its metabolites in VSMC proliferation. The major intermediate metabolites of mevalonate, geranylgeranyl-pyrophosphate (GGPP), farnesyl pyrophosphate (FPP) and IPP (isopentenyl pyrophosphate) were prepared in the form of liposomes, and the effects of GGPP, FPP and IPP on pravastatin induced inhibition of VSMC proliferation and G1 arrest were examined. Only GGPP restored the pravastatin-induced inhibition of DNA synthesis and G1 arrest. Pravastatin inhibited translocation of Rho small GTPase from cytosol to membrane. By the addition of GGPP, Rho small GTPase are geranylgeranylated and translocated to membranes during G1/S transition. These data suggest that GGPP, rather than FPP or IPP, is an essential metabolite among mevalonic acid metabolites for VSMC proliferation and the G1/S transition.

Genome sequencing analysis of the 1.8 Mb entire human MHC class I region

The human MHC class I region spans 1.8 Mb from the MICB gene to the HLA-F gene at the telomeric end of the HLA region. There are fewer genes recognized in this region than in the class II or class III region, probably because this region remained uncharacterized for genomic organization. Based on the 1,796,938 bp genomic sequence of the entire class I region determined in our laboratory, the complete gene structure of this region has finally emerged. This region embraces as many as 118 genes (73 known and 45 new genes) with a gene density of one gene every 15.2 kb, which is comparable to that of the gene-rich class III region. The GC content is fairly uniform throughout the class I region, being 45.8% on average, which corresponds to the isochore H1. By investigation of genetic polymorphisms in 26 out of 758 microsatellite repeats identified in the class I region, we could reduce the critical region for Behçet's disease (associated with B51) and psoriasis vulgaris (associated with Cw6) to approximately 50 kb segments, between MICA and HLA-B and between TCF19 and S, respectively. Thus, systematic large-scale genomic sequencing provides an efficient way of identifying genes and of mapping disease-susceptible genes in the genome.

Circadian-regulated transcription of the psbD light-responsive promoter in wheat chloroplasts

The level of mRNAs derived from the plastid-encoded psbD light-responsive promoter (LRP) is controlled by a circadian clock(s) in wheat (Triticum aestivum). The circadian oscillations in the psbD LRP mRNA level persisted for at least three cycles in continuous light and for one cycle in continuous dark, with maxima in subjective morning and minima in subjective early night. In vitro transcription in chloroplast extracts revealed that the circadian cycles in the psbD LRP mRNA level were dominantly attributed to the circadian-regulated transcription of the psbD LRP. The effects of various mutations introduced into the promoter region on the psbD LRP activity in vitro suggest the existence of two positive elements located between -54 and -36, which generally enhance the transcription activity, and an anomalous core promoter structure lacking the functional "-35" element, which plays a crucial role in the circadian fluctuation and light dependency of psbD LRP transcription activity.

rbcL Transcript levels in tobacco plastids are independent of light: reduced dark transcription rate is compensated by increased mRNA stability

The plastid rbcL gene, encoding the large subunit of ribulose-1, 5-bisphosphate carboxylase, in higher plants is transcribed from a sigma70 promoter by the eubacterial-type RNA polymerase. To identify regulatory elements outside of the rbcL -10/-35 promoter core, we constructed transplastomic tobacco plants with uidA reporter genes expressed from rbcL promoter derivatives. Promoter activity was characterized by measuring steady state levels of uidA mRNA on RNA gel blots and by measuring promoter strength in run-on transcription assays. We report here that the rbcL core promoter is sufficient to obtain wild-type rates of transcription. Furthermore, the rates of transcription were up to 10-fold higher in light-grown leaves than in dark-adapted plants. Although the rates of transcription were lower in the dark, rbcL mRNA accumulated to similar levels in light-grown and dark-adapted leaves. Accumulation of uidA mRNA from most rbcL promoter deletion derivatives directly reflected the relative rates of transcription: high in the light-grown and low in the dark-adapted leaves. However, uidA mRNA accumulated to high levels in a light-independent fashion as long as a segment encoding a stem-loop structure in the 5' untranslated region was included in the promoter construct. This finding indicates that lower rates of rbcL transcription in the dark are compensated by increased mRNA stability.

Twenty-six new polymorphic microsatellite markers around the HLA-B, -C and -E loci in the human MHC class I region

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of disease-related loci for diseases such as Behçet's disease and psoriasis vulgaris. Although many novel genes have recently been identified in this region, it still appears to be difficult to relate any of these new genes to MHC class I-associated diseases as causative genetic factors. During the course of large-scale genomic sequencing of the human MHC class I region, we identified 262 microsatellite sequences with dinucleotide to pentanucleotide repeats around the HLA-B, -C and HLA-E genes. Of these, 26 microsatellites were investigated for repeat polymorphism using 60 HLA homozygous B-cell lines and 60 healthy random individuals. The average number of alleles at these microsatellite loci was 9.6 with a PIC (polymorphism content value) of 0.69. These new polymorphic microsatellite markers will probably be very useful for precise mapping of disease-related genes within the HLA class I region in linkage analysis. Moreover, they will provide a powerful tool to study recombination events in this region, which contributes to haplotypic diversification.

[Review: the overviews of contrast echocardiography in cardiovascular disorders]

The contrast echocardiography used to be applied for the diagnosis of congenital heart diseases, analysis of right side heart hemodynamics, and the evaluation of peripheral blood flow profiles. Recently, myocardial contrast echocardiography is evoked for estimating regional coronary blood flow as a parallel procedure of interventional therapy for ischemic patients. Advanced technology such as harmonic imaging, rf signal processing and digital storage of the data are extremely supportive for the quantitative evaluation of myocardial blood flow. In addition, new contrast agents which enable interpretation of myocardial contrast could be administered by peripheral injection.

[Ultrasound scattering properties of Albunex microspheres]

In Japan, clinical and basic investigations of Albunex were started from 1989, and was firstly approved by the government as a commercially available contrast agent for the cardiovascular disorders. Although it has recently evacuated from the market, its acoustic properties proven by the many investigators were valuable for preparation of the second generation of contrast agents. Therefore, we summarized our data of the ultrasonic properties of Albunex both in vitro and experimental dog studies using RF signals. In conclusion, Albunex was a extremely sensitive blood flow tracer in evaluating intracardiac blood flow as well as intramyocardial perfusion.

Nucleotide sequencing analysis of the 146-kilobase segment around the IkBL and MICA genes at the centromeric end of the HLA class I region

To elucidate the complete gene structure and to identify new genes involved in the development of HLA class I antigen-associated diseases in the class I region of the human major histocompatibility complex on chromosome 6, a YAC clone (745D12) covering the 146-kb segment around the IkBL and MICA loci was isolated from a YAC library constructed from the B-cell line, BOLETH. A physical map of this region was constructed by isolation of overlapping cosmid clones derived from 745D12. Of these, five contiguous cosmids were chosen for DNA sequencing by the shotgun strategy to give a single contig of 146,601 bp from 2.8 kb telomeric of the IkBL gene to exon 6 of MICA. This region was confirmed to contain five known genes, IkBL, BAT1, MICB, P5-1, and HLA-X (class I fragment), from centromere to telomere, and their exon-intron organizations were determined. The 3.8-1 homologue gene (3.8-1-hom) showing 99.7% identity with the 3.8-1 cDNA clone, which was originally isolated using the 3.8-kb EcoRI fragment between the HLA-54/H and the HLA-G genes, was detected between MICA and MICB and was suggested to represent the cognate 3.8-1 genomic sequence from which the cDNA clone was derived. No evidence for the presence of expressed new genes could be obtained in this region by homology and EST searches or coding and exon prediction analyses. One TA microsatellite repeat spanning 2545 bases with as many as 913 repetitions was found on the centromeric side of the MICA gene and was indicated to be a potential hot spot for genetic recombination. The two segments of approximately 35 kb upstream of the MICA and MICB genes showed high sequence homology (about 85%) to each other, suggesting that segmental genome duplication including the MICA and MICB genes must have occurred during the evolution of the human MHC.

Electron paramagnetic resonance and mutational analyses revealed the involvement of photosystem II-L subunit in the oxidation step of Tyr-Z by P680+ to form the Tyr-Z+P680Pheo- state in photosystem II

To reveal the molecular mechanism of involvement of photosystem II (PSII)-L protein in the electron transfer in PSII, effects of mutations in PSII-L on the photochemistry of PSII were investigated by means of electron paramagnetic resonance (EPR) and flash photolysis. Wild type and a series of mutant versions of PSII-L were overproduced in Escherichia coliand chromatographically purified. Plastoquinone 9 (PQ-9) depleted PSII reaction center core complex consisting of CP47/D1/D2/Cytb-559/PSII-I/PSII-W was prepared and reconstituted with the wild type and each mutant version of PSII-L together with or without PQ-9. EPR signal indicating the formation of Tyr-Z+P680Pheo- state upon room-temperature illumination disappeared in CP47/D1/D2/Cytb-559/PSII-I/PSII-W, and it was recovered when the complex was reconstituted with the wild-type PSII-L. Mutation of a few amino acid residues in the carboxyl-terminal region of PSII-L, such as substitution of a triad of Tyr34, Phe35, and Phe36 by Leu, selectively resulted in the loss of the capability of PSII-L to recover the light-induced formation of Tyr-Z+P680Pheo- state in the reconstituted complex. Hydropathy profile of PSII-L suggests that it spans the membrane once by a hydrophobic stretch of the carboxyl-terminal side as its carboxyl end to face to the lumen. If this is the case, the amino acid residues essential for PSII-L to function are expected to be located close to the donor side of P680, suggesting the interaction of PSII-L with Tyr-Z (and/or Tyr-D) or P680 to facilitate the oxidation of Tyr-Z by P680+ to form Tyr-Z+P680Pheo- state in PSII. Evidence against PSII-L being involved in the electron transfer from Pheo- to QA was obtained by the flash photolysis experiments.

Identification of promoter elements involved in the cytosolic Ca(2+)-mediated photoregulation of maize cab-m1 expression

Changes in cytoplasmic Ca2+ levels are involved in the regulation of several plant genes. However, to our knowledge, no regions of genes or specific cis elements have been shown to be involved in the regulation of plant gene expression by cytosolic Ca2+ signaling. The maize (Zea mays) gene cab-m1, which encodes a light-harvesting chlorophyll a/b-binding apoprotein, is positively photoregulated in mesophyll cells (MC) but not in bundle-sheath cells (BSC). This gene is highly preferentially expressed in maize MC versus BSC. In situ transient expression assays have revealed that exposure of tissues to ethyleneglycol-bis(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA), which chelates Ca2+, blocks the photostimulation of cab-m1 full promoter (-1026 to + 14) activity in MC of leaf segments of dark-grown maize seedlings. EGTA has no effect on expression in BSC. These results suggest that light-induced elevation of the cytosolic Ca2+ concentration in MC is required for the enhancement of cab-m1 expression in MC. Deletion of the sequence from -1026 to -360 completely abolished Ca2+ responsiveness of cab-m1 expression in MC. On the other hand, a 54-bp fragment in the 5' flanking region (-953 to -899 relative to the translation start site) conferred Ca2+ responsiveness on a -359 core promoter: reporter gene, suggesting that Ca2+ signaling is mediated via specific sequences in this short fragment. Furthermore, possible involvement of Ca(2+)-calmodulin in the signal transduction chain for regulating cab-m1 expression was suggested by the results of inhibitor experiments.

Triplet repeat polymorphism in the NOTCH4 gene with the human major histocompatibility complex in a healthy population and patients with a salivary gland tumor in Japan

The NOTCH4 gene, the human counterpart of the mouse mammary tumor gene, int-3, has been recently localized near the boundary of the HLA class II and class III regions. This gene is one of candidates for development of salivary gland tumor. Microsatellite polymorphism of (CTG)n repeat in the signal peptide domain of NOTCH4 was analyzed in Japanese including the patients with salivary gland tumor. Four alleles consisting of 6, 9, 10 and 11 repetitions of CTG (Leu) were observed and found to be in linkage disequilibria with HLA class I and class II alleles. No significant association of this microsatellite polymorphism with the disease were observed in 26 samples of salivary gland tumor. In this neoplasia, neither large-scale deletion nor translocation was detected around the NOTCH4 gene using genomic Southern hybridization analysis by the NOTCH4 cDNA as a probe.

Mechanisms of enhanced production of PGI2 in cultured rat vascular smooth muscle cells enriched with eicosapentaenoic acid

The present investigation was performed to clarify the effect of EPA on PGI2 production in vitro using cultured rat vascular smooth muscle cells (VSMC). To simulate in vivo conditions, a triacylglycerol (TG) emulsified form of EPA was used. An increase in EPA content was achieved without alteration of arachidonic acid concentration. These experiments clearly demonstrated that co-incubation of EPA-TG increased PGI2 production by cultured VSMC in a dose dependent fashion. Among polyunsaturated fatty acid TG examined (docosahexaenoic acid, linoleic acid, oleic acid and EPA), only EPA-TG was effective. Cyclooxygenase (COX) was activated, but neither phospholipase A2 nor PGI2 synthase activity was changed. EPA treatment did not alter the amount of COX-1 and COX-2 protein in VSMC. Addition of antioxidants, such as butylated hydroxytoluene or vitamin E, decreased MDA levels in the medium and cells and reversed the enhanced PGI2 production in EPA rich-VSMC. Therefore, the high polyunsaturation of EPA could generate low levels of lipid peroxides and thereby lead to activation of COX and an increased PGI2 production. Although EPA increased PGI2 production, only a negligible amount of PGI3 was produced by rat aortic tissues. Enhanced production of PGI2 might contribute to the anti-atherogenic effect of EPA.

Nucleotide sequence analysis of the HLA class I region spanning the 237-kb segment around the HLA-B and -C genes

To elucidate the detailed gene organization of the human leukocyte antigen (HLA) class I region on chromosome 6, seven contiguous cosmid genomic clones covering the 237-kb segment around the HLA-B and -C loci were subjected to DNA sequencing by the shotgun strategy to give a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C. This region was confirmed to contain four known genes, MICA, HLA-17, HLA-B, and HLA-C, from centromere to telomere. Further, a new member of the P5 multicopy genes was found to be about 1.3 kb upstream of the HLA-17 gene and designated P5.8. Five novel genes designated NOB1-5 were identified by RT-PCR and Northern blot hybridization. In addition, two pseudogenes, dihydrofolate reductase pseudogene (DHFRP) and ribosomal protein L3 homologous gene (RPL3-Hom), were also found in the vicinity of the HLA-B and -C genes, respectively. The two segments (about 40 kb) downstream of the HLA-B and HLA-C genes showed high sequence homology to each other, suggesting that segmental genome duplication including the major histocompatibility complex (MHC) class I gene must have occurred during the evolution of the MHC.

Role of PSII-L protein (psbL gene product) on the electron transfer in photosystem II complex. 1. Over-production of wild-type and mutant versions of PSII-L protein and reconstitution into the PSII core complex

To establish a system for over-production of PSII-L protein which is a component of photosystem II (PSII) complex, a plasmid designated as pMAL-psbL was constructed and expressed in Escherichia coli JM109. A fusion protein of PSII-L and maltose-binding proteins (53 kDa on SDS-PAGE) was accumulated in E. coli cells to a level of 10% of the total protein upon isopropyl-beta-D-thiogalactopyranoside (IPTG) induction. The carboxyl-terminal part of 5.0 kDa was cleaved from the fusion protein and purified by an anion exchange column chromatography in the presence of detergents. This 5.0 kDa protein was identified as PSII-L by amino-terminal amino acid sequence analysis and the chromatographic behavior on an anion exchange gel. A few types of mutant PSII-L were also prepared by the essentially same procedure except for using plasmids which contain given mutations in psbL gene. Plastoquinone-9 (PQ-9) depleted PSII reaction center core complex consisting of D1, D2, CP47, cytochrome b-559 (cyt b-559), PSII-I and PSII-W was reconstituted with PQ-9 and digalactosyldiglyceride (DGDG) together with the wild-type or mutant PSII-L produced in E. coli or isolated PSII-L from spinach. Significant difference between the wild-type PSII-L proteins from E. coli and spinach was not recognized in the effectiveness to recover the photo-induced electron transfer activity in the resulting complexes. The analysis of stoichiometry of PQ-9 per reaction center in the PQ-9 reconstituted PS II revealed that two molecules of PQ-9 were reinserted into a reaction center independent of the presence or absence of PSII-L. These results suggest that PSII-L recovers the electron transfer activity in the reconstituted RC by a mechanism different from the stabilization of PQ-9 in the Q(A) site of PSII. Ubiquinone-10 (UQ-10), but not plastoquinone-2 (PQ-2), substituted PQ-9 for recovering the PSII-L supported electron transfer activity in the reconstituted PSII reaction center complexes. The results obtained with the mutant PSII-L proteins revealed that the carboxyl terminal part rather than amino terminal part of PSII-L is crucial for recovering the electron transfer activity in the reconstituted complexes.