Investigation of the porcine PA 28 activator Gamma-subunit (PSME3) Gene: isolation, polymorphism and its chromosomal localisation

The PA28 activator gamma-subunit encoded by the PSME3 gene is the third component of the PA28 activator complex, which is the 11S regulator of the 20S proteasome. The open reading frame (ORF) sequence of the porcine PSME3 gene encoding the proteasome activator gamma-subunits (or proteasome activator subunit 3) was determined. The deduced amino acid sequence shows 100% identity with the corresponding human and murine sequence. Two single nucleotide substitutions, one located in intron 5 (I5), the other one in exon 8 (E8), were detected using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP). Analysis on allele frequencies of the two polymorphic sites determined in different pig breeds (Duroc, Tibet, Qingping, Meishan, Erhualian and Mingzhu) showed large differences between Duroc and Chinese indigenous pig breeds investigated. The PSME3 gene was physically assigned to SSC12p11 - (2/3) p13 in the vicinity of the GH gene. This result provides an additional type I marker to the GH linkage group on SSC12.