title: A model for heterogeneous nuclear ribonucleoproteins in telomere and telomerase regulation.
abstract: The heterogeneous nuclear ribonucleoproteins (hnRNPs) are a large family of nucleic acid binding proteins that are often found in, but not restricted to, the 40S-ribonucleoprotein particle. Subsets of hnRNPs are strictly nuclear while others shuttle between the nucleus and cytoplasm. Members of the hnRNP family have been implicated to have roles in many aspects of mRNA maturation/turnover and in telomere and telomerase regulation. Telomeres are repetitive DNA elements mainly found at the ends of human chromosomes. In most normal cells, telomeres shorten with each cell division. Telomere shortening can be compensated for by a ribonucleoprotein complex, called telomerase. Telomerase, consisting of an integral RNA and catalytic protein component as well as several auxiliary factors, extends the 3'-G-rich strand of the ends of the telomeres. Here we present new data and describe a model that implicates the telomerase bound hnRNPs in promoting telomere access by interacting with telomeres. Telomere bound hnRNPs include hnRNP A1, A2-B1, D and E and telomerase bound hnRNPs including hnRNPA1 C1/C2 and D. The telomere and telomerase bound hnRNPs may prove to be good targets for regulating telomere length.
authors.affiliation: Ambion, Inc., 2130 Woodward Street, Austin, Texas, TX 78744-1832, USA.
authors.forename: Lance P
authors.initials: LP
authors.lastname: Ford
authors.forename: Woodring E
authors.initials: WE
authors.lastname: Wright
authors.forename: Jerry W
authors.initials: JW
authors.lastname: Shay
mesh_terms: D000818:Animals; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D046911:Macromolecular Substances; D008957:Models, Genetic; D012261:Ribonucleoproteins / Q000502:physiology*; D019098:Telomerase / Q000378:metabolism*; D016615:Telomere / Q000235:genetics / Q000378:metabolism*
chemical_list: C439788:C1 HNRNP; C503635:HNRNPC protein, human; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D046911:Macromolecular Substances; D012261:Ribonucleoproteins; C439768:hnRNP A2; C000619656:hnRNPA1 protein, human; D019098:Telomerase