High impact information on IGHG4

• The translocation linked the IGHG4 switch (Sgamma4) sequences of the productively rearranged allele to chromosome 1 sequences downstream of MUC1, leaving the MUC1 transcriptional unit intact [1].
• The newly found IGHG7 gene, which has a high homology to the equine IGHG4 gene, is located between the IGHG3 and IGHG4 genes [2].
• The high degree of conservation shared between the nucleotide sequences of the IGHG7 and IGHG4 genes is unusual for the IGHG genes of the horse and suggests that these two genes duplicated most recently during evolution of the equine IGHG genes [2].
• The alleles at these three closely linked loci are transmitted as Gm haplotypes, together with the IGHG4 and the IGHGP (or pseudo gamma) genes [3].
• Our data demonstrate that the restriction fragment length polymorphism is occasionally due to the presence or absence of a given restriction site as a consequence of a point mutation, such as the creation of an Eco RI site, at the codon 3 of exon 2 in one IGHG4 allele (IGHG4*D2) [4].

Biological context of IGHG4

• However, single amino acid substitutions were present in IGHG2 and IGHG4 genes, indicating the presence of IgG polymorphism possibly resulting in the expression of different allotypes [5].
• Multiple levels of analysis of an IGHG4 gene deletion [6].
• A human immunoglobulin IGHG3 allele (Gmb0,b1,c3,c5,u) with an IGHG4 converted region and three hinge exons [7].
• The structural features of the LAT IGHG3 allele, which are the lack of one hinge exon and its conversion by the IGHG4 gene, demonstrate that both crossing-over and gene conversion events occur in the evolution of the human IGHG genes [7].

Associations of IGHG4 with chemical compounds

• Moreover, we show that the LAT G3m (b0, b1, c3, c5, u) coding sequence results from the conversion, in the CH3 exon, of the G3m (b0, b1, b3, b4, b5, u, v) allele, the most frequent IGHG3 gene in the Negroid populations, by the homologous region of a IGHG4 gene [7].

References