The gene encoding rat nuclear pore glycoprotein p62 is intronless.

Glycoproteins of the nuclear pore complex are thought to play an important role in the transport of regulatory proteins and ribonucleoproteins across the nuclear envelope. However, the genetic elements and signals that control the expression of nuclear pore glycoproteins are poorly understood. To study the transcriptional regulation of mammalian nuclear pore glycoprotein biosynthesis, we have isolated the gene coding for the major rat nuclear pore glycoprotein p62. The p62 gene consists of a 2941-base pair region that is linear with the full length p62 cDNA with no intervening sequences. Quantitative Southern analysis revealed that the gene is present in single copy. The p62 gene encodes a 525-amino acid open reading frame that directs the synthesis of the 62-kDa pore glycoprotein in vitro and in transfected cultured cells. The 5'-flanking region contains two potential transcription start sites; primer extension analysis revealed that the furthest upstream site is preferentially used in vivo. When linked to a reporter gene, the 5'-flanking region of the p62 gene serves as an active promoter.