Gene frequencies of S-adenosylhomocysteine hydrolase (SAHH) in a Japanese population

Akiyama, Katsunori; Nakamura, Shigeki; Abe, Kazue

doi:10.1007/bf00279314

Cited by 9 publications

(10 citation statements)

References 4 publications

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“…Four different SAHH phenotypes could be recognized in the samples analysed and they are referred to as types SAHH 1, 2-1, 2 and 3-1. Three of them, 1, 2-1 and 2, appear identical to those described by Bissbort et al (1983) and Akiyama et al (1984). The fourth pattern, called SAHH 3-1, seems to coincide with that reported by Bissbort et al (1983) as a rare variant segregating in one family.…”

Section: Electrophoretic Properties Of Sahh Isozyrnessupporting

confidence: 69%

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Family and population studies of SAHH and ADA polymorphisms. A possible pitfall in the ascertainment of SAHH electrophoretic phenotypes

Scozzari

Sellitto

Tassone

et al. 1987

Annals of Human Genetics

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Typing of both SAHH and ADA red cell electrophoretic patterns was carried out among the members of about 80 families from Latium (Central Italy) and in a random sample of about 350 individuals from two Italian regions, Latium and Sardinia. 1. The SAHH1 enzyme product provided another interesting example of a change in the electrophoretic pattern brought about by the haemolysate ageing. In vitro storage of SAHH 1 red cell lysates leads to the production of a pattern similar to that expected from a heterozygote SAHH 2-1. This change has been shown to be abolished by pretreating the sample with mercaptoethanol. The results indicate that the systematic use of sulphydril reducing agents can provide a more reliable means of analysing the SAHH polymorphism if differently stored samples are to be compared by starch gel electrophoresis. 2. Evidence against complete linkage of the SAHH and ADA loci has been obtained from two informative SAHH/ADA matings encountered in this study. 3. The SAHH allele frequencies observed in the two samples analysed were: SAHH1 = 0.969, SAHH2 = 0.024, SAHH3 = 0.007 (Latium) and SAHH1 = 0.973, SAHH2 = 0.011, SAHH3 = 0.016 (Sardinia). 4. The ADA2 allele frequency estimates were: 0.083 (Latium) and 0.059 (Sardinia). These figures are almost identical to those already reported for the same two regions.

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Section: Electrophoretic Properties Of Sahh Isozyrnessupporting

confidence: 69%

“…A rather small number of families, however, has been studied from this viewpoint. As far as population studies are concerned, the data are so scanty (Bissbort et al 1983; Akiyama et al 1984; Corbo et al 1985) that, so far, little is known about the incidence of SAHH phenotypic variation in different ethnic groups.…”

Section: Introductionmentioning

confidence: 99%

Family and population studies of SAHH and ADA polymorphisms. A possible pitfall in the ascertainment of SAHH electrophoretic phenotypes

Scozzari

Sellitto

Tassone

et al. 1987

Annals of Human Genetics

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“…of eq. (7) and can, in principle, be computed by inverting the coupling matrix (5). In practice, this involves a computationally expensive process and, thus, we adopt a different strategy based on a direct minimization of the Helfrich Hamiltonian.…”

Section: A Energy Calculationsmentioning

confidence: 99%

“…These adhesion bonds often aggregate into macroscopically large adhesion clusters, such as focal adhesions, adherens junctions and gap junction plaques [2][3][4]. In addition to providing mechanical stability to cells, these adhesion domains are essential for numerous biological processes, including signal transduction [5], T-cell activation [6], and tissue formation [7]. Therefore, it is paramount to gain a comprehensive understanding of the biophysical principles that govern the formation of adhesion clusters.…”

Section: Introductionmentioning

confidence: 99%

Formation of semi-dilute adhesion domains driven by weak elasticity-mediated interactions

Dharan

Farago

2016

Soft Matter

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Cell-cell adhesion is established by specific binding of receptor and ligand proteins anchored in the cell membranes. The adhesion bonds attract each other and often aggregate into large clusters that are central to many biological processes. One possible origin of attractive interactions between adhesion bonds is the elastic response of the membranes to their deformation by the bonds. Here, we analyze these elasticity-mediated interactions using a novel mean-field approach. Our analysis of systems at different densities of bonds, ϕ, reveals that the phase diagram, i.e., the binodal and spinodal lines, exhibit a nearly universal behavior when the temperature T is plotted against the scaled density x = ϕξ(2), where ξ is the linear size of the membrane's region affected by the presence of a single isolated bond. The critical point (ϕc , Tc) is located at very low densities, and slightly below Tc we identify phase coexistence between two low-density phases. Dense adhesion domains are observed only when the height by which the bonds deform the membranes, h0, is much larger than their thermal roughness, Δ, which occurs at very low temperatures T≪Tc. We, thus, conclude that the elasticity-mediated interactions are weak and cannot be regarded as responsible for the formation of dense adhesion domains. The weakness of the elasticity-mediated effect and its relevance to dilute systems only can be attributed to the fact that the membrane's elastic energy saturates in the semi-dilute regime, when the typical spacing between the bonds r≳ξ, i.e., for x≲ 1. Therefore, at higher densities, only the mixing entropy of the bonds (which always favors uniform distributions) is thermodynamically relevant. We discuss the implications of our results for the question of immunological synapse formation, and demonstrate that the elasticity-mediated interactions may be involved in the aggregation of these semi-dilute membrane domains.

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“…Mohandas et al [ 1984] showed that SAHH is located on the long arm of chromosome 20 in the region cen -q 13.1, proximally to adenosin deaminase (ADA; q 13.2 -qter). Very low levels of SAHH activity have been found in children af fected by deficiency of ADA (< 2% of nor mal SAHH activity) [Hershfield et al, 1979], purine nucleoside phosphorylase (PNP; about 15% of normal SAHH activ ity) and hypoxanthine-guanine phosphorybosyl transferase (HGPRT; about 43% of normal SAHH activity) [Kaminska and Fox, 1980], The enzyme exhibits a genetic polymorphism with two common alleles which have similar gene frequencies in Germany and Japan (SAHH*1 ~0.96) [Bissbort et al, 1983;Akiyama et al, 1984],…”

Section: Introductionmentioning

confidence: 99%

Polymorphism of S-Adenosylhomocysteine Hydrolase in Italy

Corbo¹,

Palmarino²,

Schiattarella³

et al. 1987

Hum Hered

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S-adenosylhomocysteine hydrolase (SAHH) polymorphism has been investigated in the Italian population. Three common alleles, SAHH*1, SAHH*2 and SAHH*3, have been observed and the estimated gene frequencies are 0.968, 0.023 and 0.009, respectively. SAHH activity has been assayed in 50 healthy individuals and the mean activity was 0.043 ± 0.017 µmol uric acid/min/g Hb at 37 °C. Five heterozygotes for adenosine deaminase deficiency and three heterozygotes for purine nucleoside phosphorylase deficiency showed SAHH within the range of the normal distribution. The effects of some thiol reagents on red blood cell SAHH electrophoretic pattern have been investigated.

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Gene frequencies of S-adenosylhomocysteine hydrolase (SAHH) in a Japanese population

Cited by 9 publications

References 4 publications

Family and population studies of SAHH and ADA polymorphisms. A possible pitfall in the ascertainment of SAHH electrophoretic phenotypes

Family and population studies of SAHH and ADA polymorphisms. A possible pitfall in the ascertainment of SAHH electrophoretic phenotypes

Formation of semi-dilute adhesion domains driven by weak elasticity-mediated interactions

Polymorphism of S-Adenosylhomocysteine Hydrolase in Italy

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