Transcriptional and posttranscriptional regulations of the HLA-G gene

Hla-g has a relevant role in immune response regulation. the overall structure of the hla-g coding region has been maintained during the evolution process,in which most of its variable sites are synonymous mutations or coincide with introns,preserving major functional hla-g properties. the hla-g promoter region is different from the classical class i promoters,mainly because (i) it lacks regulatory responsive elements for ifn-γ and nf-κb,(ii) the proximal promoter region (within 200 bases from the first translated atg) does not mediate transactivation by the principal hla class i transactivation mechanisms,and (iii) the presence of identified alternative regulatory elements (heat shock,progesterone and hypoxia-responsive elements) and unidentified responsive elements for il-10,glucocorticoids,and other transcription factors is evident. at least three variable sites in the 3′ untranslated region have been studied that may influence hla-g expression by modifying mrna stability or microrna binding sites,including the 14-base pair insertion/deletion,+3142c/g and +3187a/g polymorphisms. other polymorphic sites have been described,but there are no functional studies on them. the hla-g coding region polymorphisms might influence isoform production and at least two null alleles with premature stop codons have been described. we reviewed the structure of the hla-g promoter region and its implication in transcriptional gene control,the structure of the hla-g 3′utr and the major actors of the posttranscriptional gene control,and,finally,the presence of regulatory elements in the coding region. © 2014 erick c. castelli et al.