This gene encodes a nuclear protein that functions in the regulation of polyadenylation and promotes gene expression. The protein forms a high-molecular weight complex with components of the polyadenylation machinery. It is thought to serve as a scaffold for recruiting regulatory factors to the polyadenylation complex. It also participates in 3′-end maturation of histone mRNAs, which do not undergo polyadenylation. The protein also localizes to the cytoplasmic plaques of tight junctions in some cell types.^[2]

Model organisms have been used in the study of SYMPK function. A conditional knockout mouse line, called Sympk^{tm1a(EUCOMM)Wtsi[7][8]} was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.^[9][10][11]

Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion.^[5][12] Twenty five tests were carried out on mutant mice and two significant abnormalities were observed.^[5] No homozygous mutant embryos were identified during gestation, and thus none survived until weaning. The remaining tests were carried out on heterozygous mutant adult mice; no additional significant abnormalities were observed in these animals.^[5]

SYMPK has been shown to interact with CSTF2^[13] and HSF1.^[14]