PMC:2728203 / 4615-5873 JSONTXT

{"project":"2_test","denotations":[{"id":"18190927-16141059-62517963","span":{"begin":134,"end":135},"obj":"16141059"},{"id":"18190927-17786152-62517963","span":{"begin":134,"end":135},"obj":"17786152"},{"id":"18190927-16682182-62517963","span":{"begin":134,"end":135},"obj":"16682182"},{"id":"18190927-11779864-62517964","span":{"begin":428,"end":430},"obj":"11779864"},{"id":"18190927-11927564-62517964","span":{"begin":428,"end":430},"obj":"11927564"},{"id":"18190927-11927564-62517965","span":{"begin":483,"end":485},"obj":"11927564"},{"id":"18190927-8483450-62517966","span":{"begin":707,"end":709},"obj":"8483450"},{"id":"18190927-12531921-62517967","span":{"begin":729,"end":731},"obj":"12531921"},{"id":"18190927-12531921-62517968","span":{"begin":842,"end":844},"obj":"12531921"},{"id":"18190927-15137937-62517969","span":{"begin":992,"end":994},"obj":"15137937"},{"id":"18190927-14718167-62517969","span":{"begin":992,"end":994},"obj":"14718167"},{"id":"18190927-10085285-62517970","span":{"begin":1053,"end":1055},"obj":"10085285"}],"text":"Heterogeneous nuclear ribonucleoproteins (hnRNPs) are important in orchestrating the different steps of the gene expression pathway.1–3 One important hnRNP function is to sort export-competent mRNPs and concentrate them in the vicinity of NPCs to facilitate export. Nuclear abundant poly(A) RNA-binding protein (Nab2) is an essential multidomain hnRNP that is required for the nuclear export of poly(A) mRNA in S. cerevisiae.18,19 Nab2 is also involved in poly(A) tail length control19 and has been proposed to provide a link between the termination of polyadenylation and mRNA nuclear export. Nab2 interacts with Mlp1, which is constructed from a long α-helical coiled coil and a globular C-terminal domain20 that binds to Nab2.21 Overexpression of Mlp1 or its C-terminal domain causes retention of both Nab2 and poly(A)+ RNA in the nucleus.21 Mlp1 is itself attached to the nucleoplasmic face of NPCs and, hence, is thought to facilitate coordination of several steps in mRNA metabolism,15,16 albeit the Mlp proteins are not essential for cell growth.17 Because it both recognizes the presence of a poly(A) tail and interacts with Mlp1, Nab2 is an attractive candidate to participate in the final step of the nuclear portion of the gene expression pathway."}