Description_x000D_ General description_x000D_ Inhibition of the nuclear export of poly(A)-containing mRNAs caused by the influenza A virus NS1 protein requires its effector domain. The NS1 effector domain functionally interacts with the cellular 30 kDa subunit of cleavage and polyadenylation specific factor 4, an essential component of the 3′ end processing machinery of cellular pre-mRNAs. In influenza virus-infected cells, the NS1 protein is physically associated with cleavage and polyadenylation specific factor 4, 30kD subunit. Binding of the NS1 protein to the 30 kDa protein in vitro prevents CPSF binding to the RNA substrate and inhibits 3′ end cleavage and polyadenylation of host pre-mRNAs. Thus the NS1 protein selectively inhibits the nuclear export of cellular, and not viral, mRNAs. Multiple alternatively spliced transcript variants that encode different isoforms have been described for this gene. (provided by RefSeq)_x000D_ Immunogen_x000D_ CPSF4 (AAH50738.1, 1 a.a. ~ 243 a.a) full-length human protein._x000D_ Sequence_x000D_ MQEIIASVDHIKFDLEIAVEQQLGAQPLPFPGMDKSGAAVCEFFLKAACGKGGMCPFRHISGEKTVVCKHWLRGLCKKGDQCEFLHEYDMTKMPECYFYSKFGECSNKECPFLHIDPESKIKDCPWYDRGFCKHGPLCRHRHTRRVICVNYLVGFCPEGPSCKFMHPRFELPMGTTEQPPLPQQTQPPAKRTPQVIGVMQSQNSSAGNRGPRPLEQVTCYKCGEKGHYANRCTKGHLAFLSGQ_x000D_ Physical form_x000D_ Solution in phosphate buffered saline, pH 7.4