Genetics of human S-adenosylhomocysteine hydrolase. A new polymorphism in man

Summary A specific staining procedure for the demonstration of S-adenosylhomocysteine hydrolase (SAAH, EC 3.3.1.1) is given. The enzyme has a broad tissue distribution and is also present in erythrocytes. The SAHH gene is polymorphic in the population of southwest Germany with two common alleles: SAHH ^*1=0.96 and SAHH ^*1=0.04. Family studies resulted in the expected segregation ratios. No evidence for close linkage with a total of 25 marker loci was found. But information from human mouse somatic-cell hybrids led to the localization of the SAHH gene to human chromosome 20, thereby confirming the findings of Hershfield and Francke (1982).Dedicated to Professor Dr. P. E. Becker on the occasion of his 75th birthday     

Liver glutathione S-transferase polymorphism in Japanese and its pharmacogenetic importance

Summary A total of 168 autopsy liver extracts from Japanese individuals were examined for the glutathione S-transferase (GST) isozymes by means of starch gel electrophoresis. The gene frequencies of GST1^*1, GST1^*2, and GST1^*0 in Japanese were 0.252, 0.057, and 0.691, respectively. GST1^*3 was detected as a rare variant allele. The incidence of GST1 0 in 41 liver biopsy samples from patients suffering from various liver diseases was investigated using polyacrylamide gel isoelectric focusing. The GST1 0 phenotype was found more frequently in livers with hepatitis and carcinoma than in control livers. The isozymes coded by different GST loci were partially purified and characterized to study their biochemical properties. The apparent Km values with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate for the isozymes at the GST1, GST2, GST3, and GST4 loci were 604, 1345, 776 and 591 M, respectively.     

Four variants of human plasma α2-glycoprotein (ZAG) in the Japanese population

Summary Zn-₂-glycoprotein (ZAG) of plasma from the general Japanese adult population (n=1224) was studied by polyacrylamide gel isoelectric focusing (IEF) followed by immunoblotting with specific antiserum to ZAG. Most of the plasmas showed a common band pattern, while 16 samples showed four other patterns. These ZAG band patterns were easily differentiated by desialyzing the samples prior to IEF. The asialo form of ZAG commonly showed a single band. The 16 plasma samples presenting double bands were classified into four types containing the common single band. The differences in ZAG phenotypes may be suggested to be due to amino acid substitutions of the ZAG molecule. The statistical frequencies of five alleles, which we proposed to designate ZAG^*1, ZAG^*2, ZAG^*3, ZAG^*4, and ZAG^*5, were 0.9935, 0.0025, 0.0016, 0.0004, and 0.0020, respectively. The genetic transmission of the rare alleles ZAG^*3 and ZAG^*4 was confirmed by two family studies.     

Genetic polymorphism of complement C6 and haplotype analysis between C6 and C7 in a Japanese population

Summary Genetic polymorphism of C6 in the Japanese population has been described using polyacrylamide gel isoelectric focusing electrophoresis followed by the electrophoretic blotting technique, and haplotype analysis between C6 and C7 has also been investigated. In 565 plasma samples five different common patterns and three rare variant patterns were observed, and these were controlled by autosomal codominance at a single locus with three common and one rare alleles. These alleles were designated C6^*B, C6^*A, C6^*B2, and C6^*M, and gene frequencies were estimated to be 0.50265, 0.43186, 0.06018, and 0.00531 for C6^*B, C6^*A, C6^*B2, and C6^*M, respectively. It is noteworthy that C6^*B2 has a polymorphic frequency in the Japanese population. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. Two combinations between C6 and C7 alleles, namely C6B-C7B and C6M-C7B, were shown to be in significant positive linkage disequilibrium. The presence of allelic combinations showing linkage disequilibrium suggests the close proximity between the C6 and C7 loci.     

Discovery of a genetic polymorphism of human plasma protein C inhibitor (PCI): genetic survey utilizing isoelectric focusing followed by immunoblotting,immunological and biochemical characterization

Summary The objectives of this study were to determine the genetic basis of the electrophoretic differences of human plasma protein C inhibitors (PCI) from 977 individuals. Three discrete antibodies were produced against the PCI purified from human plasma and peptides that corresponded to the N-terminal 15 amino acid residues and the C-terminal 15 residues of human PCI, the chemical structures of which were determined by cDNA sequence analysis. The combined techniques of polyacrylamide gel isoelectric focusing and immunoblotting with these three different antibodies resolved the plasma PCI into several isoprotein bands, with a pH range of 6–7. These PCI isoproteins, however, were not stained by anti-human kallikrein, anti-human protein C or anti-human urokinase antibodies. Therefore, each of the PCI bands, which were detected by immunoblotting with the anti-PCI antibody and the two different anti-peptide antibodies, were derived from free PCI, and not an inactive PCI species. Two common phenotypes, designated PCI 1 and 1–2, were recognized, and family studies showed that they represented homozygosity or heterozygosity for two autosomal codominant alleles, PCI ^*1 and PCI ^*2. A population study of plasma samples collected from 977 Japanese individuals indicated that the frequencies of the PCI ^*1 and PCI ^*2 alleles were 0.988 and 0.012, respectively.     

Genetically polymorphic α-l-fucosidase (FUCA1) isozymes detected in blood plasma

The main isozyme patterns of desialylated blood plasma or serum -l-fucosidase (FUCA) were found to be almost identical to those of semen, urine, placental extracts, and leukocyte lysates, when detected by polyacrylamide gel isoelectric focusing, and activity staining using the fluorogenic substrate 4-methylumbelliferyl--l-fucopyranoside. Three phenotypes (1, 2-1, and 2) determined from plasma samples were identical to the phenotypes from urine and leukocyte lysates from the same individuals. A population study of plasma samples collected from 485 Japanese individuals indicated that the frequencies of the FUCA11 ^* and FUCA12 ^* alleles were 0.7505 and 0.2495, respectively. The mean plasma enzyme activities (+SD) of the three phenotypes were 318.8 ± 116.7 nmol/ml per h for type 1, 268.0 ± 108.3 nmol/ml per h for type 2-1, and 233.2 ± 84.4 nmol/ml per h for type 2. The mean activities of types 1 and 2 suggest that, on average, the FUCA11 ^* gene product in plasma has about 1.4 times the activity of FUCA12 ^*.     

Orosomucoid (ORM) typing by isoelectric focusing: evidence for gene duplication of ORM1 and genetic polymorphism of ORM2

Summary It has been demonstrated that the genetic polymorphism of human serum orosomucoid (ORM) is controlled by polymorphic ORM1 and monomorphic ORM2 loci. In this study a Japanese family was encountered in which several members had puzzling electrophoretic patterns consisting of four bands. The ORM patterns were due to the products of a duplicated ORM1 locus haplotype (ORM1 ^* 2·1) or the products of new variant alleles at the ORM2 locus. The ORM1 ^* 2·1 haplotype is very common in the Japanese population, occurring at an allele frequency of 0.16. The increased occurrence of ORM1 2-1 and the heterogeneity in band intensity among ORM1 2-1 phenotypes could be explained in terms of a duplicated gene ORM1 ^* 2·1. The ORM2 locus proved to be polymorphic, with six alleles in the Japanese population. Dedicated to Professor Dr. K. Nishigami on the occasion of his 60th birthday     

Allozyme variability ofoncorhynchus nerka in japan

We examined allozymic variation in 65 protein-coding loci in three samples of sockeye salmon (Oncorhynchus nerka) from Hokkaide, and Honshu, Japan, Over-all, six variable loci were seen and each of the three samples was variable at 3–5 loci. Two loci,mAH-1,2 ^* andALAT ^*, were variable at the P_0,95 level. Average heterozygosity ranged from 0.012 to 0.013, representing some of the lowest recorded values for the species. Although frequencies ofALAT ^* alleles differed significantly among the three samples, the overallχ ² for six polymorphic loci was not statistically significant. New data for four Russian samples at 45–64 loci were also obtained. In comparison to the Japanese samples, three samples from the Kamchatka Peninsula had two to three times the level of variation; and a sample from Iturup Island (Kuril Island archipelago) was slightly more variable. Although the anadromous sockeye salmon were originally planted from Iturup Island to Lake Shikotsu, a close genetic affinity was not indicated. These seven samples ofO. nerka were compared with representative samples previously studied in North America using five polymorphic loci. Two large groups of samples were indicated in multilocus analyses: 1) a cluster of the seven Asian samples, one Alaskan sample, and one northern British Columbia sample; and 2) a group that included a southern British Columbia sample (Fraser River), and samples from the Columbia River and Washington. We discuss these findings in light of maintaining viable populations of both forms ofO. nerka.     

Orosomucoid (ORM) typing by isoelectric focusing: evidence for two structural loci ORM1 and ORM2

Summary Orosomucoid (ORM) phenotyping was performed by isoelectric focusing and immunoprinting. The band patterns of desialyzed ORM indicated that the ORM system is controlled by two structural loci ORM1 and ORM2. In a total of 253 samples from two Caucasoid populations, five phenotypes determined by three polymorphic alleles, ORM1 ^*1, ORM1 ^*2, and ORM1 ^*3 were identified. The ORM1 ^*3 was characteristic of the Caucasoids. The ORM2 locus was monomorphic.     

HLA-G gene polymorphism in a Japanese population

 Polymorphism of the HLA-G gene in a Japanese population was investigated employing polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis, PCR sequence-specific oligonucleotide (SSO) analysis, and DNA direct sequencing. Nucleotide sequence variations in exons 2, 3, and 4 of the HLA-G gene in 54 healthy Japanese individuals were examined. In addition, seven Japanese samples carrying common HLA haplotypes were analyzed. In total, nine single-base substitutions compared with the sequence of G ^* 01011 were identified: one in intron 1 (nucleotide position 970), one in exon 2 (the third base of codon 57: G → A), three in intron 2 (1264, 1276, and 1292), three in exon 3 (the third base of codon 93: C → T, the third base of codon 107: A → T, and the first base of codon 110: C → A), and one in intron 3 (2334). The substitution at codon 110 was non-synonymous and led to an amino acid substitution from leucine to isoleucine. The other three nucleotide substitutions in exons were synonymous. Through analysis of combinations of the exon 2, 3, and 4 nucleotide sequences we identified four alleles, which we provisionally designated GJ1, GJ2, GJ3, and GJ4. The allele frequencies were estimated to be 0.33, 0.16, 0.45, and 0.06, respectively. Nucleotide sequences of GJ1, GJ2, and GJ4 were identical to G ^* 01011, the clone 7.0E, and G ^* 01013, respectively. GJ3 was a newly observed allele and was officially designated G ^* 0104 by the WHO Nomenclature Committee in January 1996. Strong positive associations were observed between HLA-G alleles and HLA-A, -B, or -DRB1 alleles. Received: 15 February 1996 / Revised: 26 March 1996     

A “new” genetic polymorphism of a human serum protein: inter-alpha-trypsin-inhibitor

Summary A new genetic polymorphism of a human serum glycoprotein, the inter--trypsin-inhibitor (ITI), has been demonstrated by population and family studies. Sera were examined after neuraminidase treatment by isoelectric focusing on agarose gels followed by immunoblotting or by immunfixation with specific ITI-antiserum. Using this method, three common ITI phenotypes 1, 1–2 and 2, as well as two further rare ITI types 1–3 and 2–3 were disclosed. Genetically, these phenotypes are controlled by three allelic genes that determine a total of six phenotypes. These alleles are designated ITI^*1, ITI^*2 and ITI^*3. The homozygous form of the third allele ITI^*3 has not been found, as yet. The frequencies of ITI were examined in two population samples from Southern Germany (n=248) and from Tyrol, Austria (n=124). The gene frequencies of the common alleles ITI^*1 and ITI^*2 were 0.575 and 0.417, respectively, in Southern Germany, and 0.577 and 0.423, respectively, in Tyrol, Austria. The third allele ITI^*3 was found only in the sample from Southern Germany, thus far, and was calculated to be 0.008.     

Genetic Population Structure of Pacific Hake, Merluccius productus, in the Pacific Northwest

This study presents the first protein electrophoretic study of population structure within the Georgia Basin Pacific hake Distinct Population Segment, as defined under the U.S. Endangered Species Act. Forty-one allozyme loci (29 polymorphic) were analyzed in samples from three Pacific hake spawning populations on the west coast of North America: (1) Port Susan, Puget Sound, Washington (three temporal samples); (2) south-central Strait of Georgia, British Columbia, Canada (two temporal samples); and (3) offshore of southern California (two temporal samples) (total n = 664). Mean heterozygosity over all loci was 12–13% for all populations. Within-population temporal samples were not significantly different from one another, but statistically significant differences were detected at 15 of the 29 polymorphic loci (p < 0.05) among the three populations. Differences at eight of these loci were highly significant (p < 0.001): ADA ^*, ALAT ^*, bGALA ^*, GPI-A ^*, sIDHP ^*, LDH-A ^*, MPI ^*, and PEP-B ^*. The two Georgia Basin populations were significantly different at six loci: bGALA ^*, sIDHP ^*, LDH-A ^*, MPI ^*, PGK ^*, and PGM-2 ^* (p < 0.05). Nei's genetic distance (D) was 0.0006 between Port Susan and Strait of Georgia pooled temporal samples, and 0.005 between these populations and offshore Pacific hake. F_ST was 0.02 and 0.0046 among all three populations and among the Georgia Basin populations, respectively. Both F_ST estimates were significantly greater than zero, and the results suggest a high degree of demographic isolation among all three populations.     

Genetic polymorphism of human urine deoxyribonuclease I

Summary A genetic polymorphism of human urine deoxyribonuclease I (DNase I) has been detected by the technique of polyacrylamide gel isoelectric focusing (IEF-PAGE) followed by immunoblotting with anti-DNase I antibody. Family studies showed that the three common phenotypes —DNASE1 1, 1–2, and 2 — and the other four rare phenotypes — DNASE1 1–3, 2–3, 2–4, and 3–4 — represent homozygosity or heterozygosity for four autosomal codominant alleles, DNASE1 ^* 1, ^* 2, ^* 3, and ^* 4. The frequencies of the DNASE1 ^* 1, DNASE1 ^* 2, DNASE1 ^* 3, and DNASE1 ^* 4 alleles in a studied Japanese population were 0.5453, 0.4396, 0.0117, and 0.0034, respectively.     

Characterization of mutants of the vitamin D-binding protein/group-specific component: molecular evolution of GC*1A2 and GC*1A3, common in some Asian populations

A well defined polymorphism of vitamin D-binding/ group-specific component (GC) resides in exon 11. To characterize the molecular basis of GC^*1A2 and GC^*1A3, common in some Asian populations, we analyzed all coding exons amplified by the polymerase chain reaction. GC^*1F was divided into GC^*1F^c and GC^*1F^T by a C-T transition in the third nucleotide of the codon (TGC/T) for cysteine²⁸³ in exon 8. The sequencing of exons 8 and 11 showed that GC^*1A2 and GC^*1A3 had occurred on a GC^*1F^c genetic background. They also shared a substitution of cysteine (TGC) for arginine (CGC) at position 429 in exon 11. GC^*1A2 was characterized by having glycine (GGC) instead of serine (AGC) at position 335 in exon 9. GC^*1A2 evolved from GC^*1F^T by three mutational events, i.e. GC^*1F^TGC^*1F^cGC^*1A3 GC^*1A2. No evidence was obtained for the existence of the duplicated gene GC^*1F · 1A2 suggested by isoelectric focusing (IEF) of serum samples. The idea that the characteristic banding pattern of GC^*1F · 1A2 after IEF results from partial formation of a disulfide bond in the additional cysteine at position 429 is discussed.Deceased     

Genetic polymorphism of the seventh component of complement in a Japanese population

Summary Genetic polymorphism of C7 in a Japanese population has been described, using polyacrylamide gel isoelectric focusing electrophoresis followed by an electrophoretic blotting technique. Phenotypes of C7 were classified into six common patterns, and observed phenotypes were produced by autosomal codominant at a single locus with three alleles. Three common alleles, designated C7^*B, C7^*M and C7^*A, were found, and gene frequencies calculated from 494 individuals showed C7^*B=0.858, C7^*M=0.096 and C7^*A=0.046, respectively. It is noteworthy that both C7^*M and C7^*A have polymorphic frequencies in the Japanese population. The distribution of phenotypes fitted the Hardy-Weinberg equilibrium. Results indicate that the electrophoretic blotting technique, which has high specificity and sensitivity, is applicable in the study of heterogeneity of protein antigens.     

Regulation of S-Adenosylhomocysteine Hydrolase by Lysine Acetylation

S-Adenosylhomocysteine hydrolase (SAHH) is an NAD⁺-dependent tetrameric enzyme that catalyzes the breakdown of S-adenosylhomocysteine to adenosine and homocysteine and is important in cell growth and the regulation of gene expression. Loss of SAHH function can result in global inhibition of cellular methyltransferase enzymes because of high levels of S-adenosylhomocysteine. Prior proteomics studies have identified two SAHH acetylation sites at Lys⁴⁰¹ and Lys⁴⁰⁸ but the impact of these post-translational modifications has not yet been determined. Here we use expressed protein ligation to produce semisynthetic SAHH acetylated at Lys⁴⁰¹ and Lys⁴⁰⁸ and show that modification of either position negatively impacts the catalytic activity of SAHH. X-ray crystal structures of 408-acetylated SAHH and dually acetylated SAHH have been determined and reveal perturbations in the C-terminal hydrogen bonding patterns, a region of the protein important for NAD⁺ binding. These crystal structures along with mutagenesis data suggest that such hydrogen bond perturbations are responsible for SAHH catalytic inhibition by acetylation. These results suggest how increased acetylation of SAHH may globally influence cellular methylation patterns.     

Genetic polymorphism of human complement component C81 in the Japanese population

Summary Genetic polymorphism of human C81 has been investigated using polyacrylamide gel isoelectric focusing (PAGIEF) in the presence of 3.1 M urea followed by electroblotting with enzyme immunoassay. In 448 individuals phenotypes of C81 were classified into three common and four rare patterns, and these were considered to be controlled by two common alleles, C81^*A and C81^* B, and three rare alleles which were tentatively designated C81^*A1J and C81^*A2J for acidic variants and C81^*B1J for the basic variant. The alleles of C81^*A2J and C81^*B1J are new rare alleles, but C81^*A1J might correspond to C81^*A1 in the former studies. Family data were in accordance with the hereditary rules. The gene frequencies were estimated as C81^*A is 0.6228, C81^*B is 0.3672, C81^*A1J is 0.0078, C81^*A2J is 0.0011, and C81^*B1J is 0.0011, respectively. The gene frequencies of the two common alleles agreed approximately with other ethnic groups. PAGIEF of neuraminidase-treated plasma samples followed by electroblotting with enzyme immunoassay is applicable to the study of heterogeneity of C81.     

Polymorphism of BF,C2, and GLO in Japanese patients with insulin-dependent diabetes mellitus: Confirmation of an increase of BF *FT

Summary The distribution of phenotypes controlled by three HLA-linked loci BF, C2, and GLO has been studied in Japanese patients with insulin-dependent diabetes mellitus (IDDM). A slight but significant higher incidence of a rare varian BF ^*FT (=^* F075) in patients was confirmed in the combined data with our previous study (Tokunaga et al. 1981 b). No significant association of C2 and GLO alleles with IDDM was found.     

Orosomucoid (ORM 1) subtyping and formal genetics

Summary Orosomucoid (ORM) phenotyping has been performed in 141 families with 407 children from southwest Germany. Eight families were observed in which duplicated ORM1 genes, F1F2, F1F3, segregated. The family data gave no information about the presence of tandemly duplicated ORM1 F1F4 and ORM1 F1F5 genes. To date, the segregation of the phenotypes of the children agrees with the extended formal model: two ORM1 loci with two common (^*F1, ^*S) and several rare (^*F1F2, ^*F1F3, ^*F4, ^*F5) alleles. The parental allele frequencies were calculated by gene counting as ORM1 ^*F1 = 0.5781, ^*S = 0.3901, ^*F1F2 = 0.0195, ^*F4 = 0.0053, ^*F1F3 = 00.0035, ^*F5 = 0.0035.