Features of the two gene pairs RD-SKI2W and DOM3Z-RP1 located between complement component genes factor B and C4 at the MHC class III region

10.2741/yang ◽  
2001 ◽  
Vol 6 (1) ◽  
pp. d927 ◽  
Author(s):  
Zhenyu Yang
Keyword(s):  
Complement Component ◽  
Class Iii ◽  
Factor B ◽  
Gene Pairs ◽  
Mhc Class Iii

Biosynthesis and secretion of MHC class III gene products (complement C4 and factor B) in the exocrine pancreas

1997 ◽  
Vol 32 (3) ◽  
pp. 367-373 ◽  
Author(s):  
Ken-ichi Sumiyoshi ◽  
Akira Andoh ◽  
Yoshihide Fujiyama ◽  
Hitoshi Sakumoto ◽  
Tadao Bamba
Keyword(s):  
Exocrine Pancreas ◽  
Gene Products ◽  
Class Iii ◽  
Factor B ◽  
Complement C4 ◽  
Mhc Class Iii

Expression of the MHC class III genes

1984 ◽  
Vol 306 (1129) ◽  
pp. 355-366 ◽  
Keyword(s):  
Gene Expression ◽  
Guinea Pig ◽  
Molecular Mechanisms ◽  
Quantitative Difference ◽  
Mononuclear Phagocytes ◽  
Model Systems ◽  
Mrna Levels ◽  
Class Iii ◽  
Factor B ◽  
Mhc Class Iii

The second (C2) and fourth (C4) components of complement and factor B (B) are coded for by genes within the major histocompatibility complex (MHC). These proteins are synthesized in liver and in extrahepatic mononuclear phagocytes. The isolation of complementary DNA probes corresponding to each of these proteins now permits analysis of the molecular mechanisms controlling expression of the class III MHC genes. Genetic control of C4 gene expression has been examined in two model systems. A defect in post transcriptional processing of C4-specific RNA accounts for a failure to generate mature C4 mRNA in homozygous deficients of a C4 deficient guinea-pig strain. On the other hand, a quantitative difference in the amounts of mature C4 liver mRNA accounts for the genetic variation in C4 levels observed among several mouse strains. The maturation of monocytes to macrophages results in changes in biosynthesis of the MHC class III products; for example, a significant increase in rate of secretion of C2 and B is noted in human monocytes during the first 3 d in culture and the proportion of C2-producing cells is greater in freshly isolated macrophages than in monocytes. Macrophages demonstrate selective increases in factor B and C2 mRNA characteristic of specific tissues. In the guinea-pig macrophage, C4 gene expression is regulated by a selective feedback mechanism induced by extracellular native C4. The C4 binds to the macrophage cell surface mediating a change in transcription or, less likely, a change in stability of C4 mRNA. Regulation of C4 synthesis in the mouse macrophage is accomplished by mechanisms that are independent of this feedback control but the murine cells also display separate mechanisms for regulation of C4 and factor B-specific mRNA levels. Resident and elicited macrophages from either mouse or guinea-pig differ with respect to expression of the class III MHC gene products. These studies form the basis for evaluating the molecular regulation of inflammation, maturation of mononuclear phagocytes and the genetic variants and deficiencies of complement proteins.

scholarly journals cis and trans elements differ among mouse strains with high and low extrahepatic complement factor B gene expression.

1992 ◽  
Vol 175 (2) ◽  
pp. 471-479 ◽  
Author(s):  
G Garnier ◽  
B Ault ◽  
M Kramer ◽  
H R Colten
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Alternative Pathway ◽  
Constitutive Expression ◽  
Mouse Strains ◽  
Complement Factor ◽  
Class Iii ◽  
Factor B ◽  
Tissue Specific ◽  
Mhc Class Iii

Factor B (Bf), an enzyme of the alternative pathway of complement activation, is one of four major histocompatibility complex (MHC) class III genes. To ascertain the genetic mechanism for tissue-specific constitutive and regulated expression of Bf, we sequenced the regulatory regions 5' of the gene from mice of different H-2 MHC haplotypes and assessed trans-acting factors, specific DNA binding nucleoproteins, in liver and kidney. Striking tissue-specific differences in constitutive expression of Bf were demonstrated in mice of H-2f or H-2z haplotypes when compared with H-2d or H-2u (kidney and intestinal Bf in H-2d or H-2u much greater than H-2f or H-2z). These differences correlated with a point nucleotide substitution 3 bp downstream of the upstream Bf initiation site that affects interaction with a DNA binding protein. This and additional cis differences localize the sequence substitutions responsible for previously identified restriction fragment length polymorphisms among inbred mouse strains and also reveal two previously unrecognized polymorphisms generated by SmaI and HinfI digestion. Evidence for differences in trans was found in a comparison of DNA binding nucleoproteins from kidney, but not liver, of B10.PL when compared with B10.M. These data, together with the high degree of sequence homology between human and mouse Bf 5' flanking regions, should prompt a search for polymorphic restriction sites and cis binding elements in the Bf promoter that could serve as markers of human MHC-associated renal pathology and variants in local MHC class III gene expression.

scholarly journals Deficiencies of Human Complement Component C4a and C4b and Heterozygosity in Length Variants of RP-C4-CYP21-TNX (Rccx) Modules in Caucasians

2000 ◽  
Vol 191 (12) ◽  
pp. 2183-2196 ◽  
Author(s):  
Carol A. Blanchong ◽  
Bi Zhou ◽  
Kristi L. Rupert ◽  
Erwin K. Chung ◽  
Karla N. Jones ◽  
...  
Keyword(s):  
Gene Dosage ◽  
Molecular Genetic ◽  
Endogenous Retrovirus ◽  
Molecular Genetic Analysis ◽  
Complement Component ◽  
Class Iii ◽  
Gene Deletions ◽  
Gene Size ◽  
Human Genomes ◽  
Mhc Class Iii

The complement component C4 genes located in the major histocompatibility complex (MHC) class III region exhibit an unusually complex pattern of variations in gene number, gene size, and nucleotide polymorphism. Duplication or deletion of a C4 gene always concurs with its neighboring genes serine/threonine nuclear protein kinase RP, steroid 21-hydroxylase (CYP21), and tenascin (TNX), which together form a genetic unit termed the RCCX module. A detailed molecular genetic analysis of C4A and C4B and RCCX modular arrangements was correlated with immunochemical studies of C4A and C4B protein polymorphism in 150 normal Caucasians. The results show that bimodular RCCX has a frequency of 69%, whereas monomodular and trimodular RCCX structures account for 17.0 and 14.0%, respectively. Three quarters of C4 genes harbor the endogenous retrovirus HERV-K(C4). Partial deficiencies of C4A and C4B, primarily due to gene deletions and homoexpression of C4A proteins, have a combined frequency of 31.6%. This is probably the most common variation of gene dosage and gene size in human genomes. The seven RCCX physical variants create a great repertoire of haplotypes and diploid combinations, and a heterozygosity frequency of 69.4%. This phenomenon promotes the exchange of genetic information among RCCX constituents that is important in homogenizing the structural and functional diversities of C4A and C4B proteins. However, such length variants may cause unequal, interchromosomal crossovers leading to MHC-associated diseases. An analyses of the RCCX structures in 22 salt-losing, congenital adrenal hyperplasia patients revealed a significant increase in the monomodular structure with a long C4 gene linked to the pseudogene CYP21A, and bimodular structures with two CYP21A, which are likely generated by recombinations between heterozygous RCCX length variants.

scholarly journals Lethal deletion of the complement component C4 and steroid 21-hydroxylase genes in the mouse H-2 class III region, caused by meiotic recombination.

1987 ◽  
Vol 84 (9) ◽  
pp. 2819-2823 ◽  
Author(s):  
T. Shiroishi ◽  
T. Sagai ◽  
S. Natsuume-Sakai ◽  
K. Moriwaki
Keyword(s):  
Meiotic Recombination ◽  
Complement Component ◽  
Class Iii

scholarly journals The Association Between Complement Component 2/Complement Factor B Polymorphisms and Age-related Macular Degeneration: A HuGE Review and Meta-Analysis

2012 ◽  
Vol 176 (5) ◽  
pp. 361-372 ◽  
Author(s):  
Ammarin Thakkinstian ◽  
Mark McEvoy ◽  
Usha Chakravarthy ◽  
Subhabrata Chakrabarti ◽  
Gareth J. McKay ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Meta Analysis ◽  
Complement Component ◽  
Age Related Macular Degeneration ◽  
Complement Factor ◽  
Factor B ◽  
Complement Factor B ◽  
Age Related

Studies on esterolytic activity of alternative complement component factor B

1983 ◽  
Vol 742 (2) ◽  
pp. 318-323 ◽  
Author(s):  
Nobuhiko Ikari ◽  
Yuji Hitomi ◽  
Michio Niinobe ◽  
Setsuro Fujii
Keyword(s):  
Complement Component ◽  
Factor B ◽  
Component Factor ◽  
Alternative Complement ◽  
Esterolytic Activity
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