title: Dual targeting and retrograde translocation: regulators of plant nuclear gene expression can be sequestered by plastids.
abstract: Changes in the developmental or metabolic state of plastids can trigger profound changes in the transcript profiles of nuclear genes. Many nuclear transcription factors were shown to be controlled by signals generated in the organelles. In addition to the many different compounds for which an involvement in retrograde signaling is discussed, accumulating evidence suggests a role for proteins in plastid-to-nucleus communication. These proteins might be sequestered in the plastids before they act as transcriptional regulators in the nucleus. Indeed, several proteins exhibiting a dual localization in the plastids and the nucleus are promising candidates for such a direct signal transduction involving regulatory protein storage in the plastids. Among such proteins, the nuclear transcription factor WHIRLY1 stands out as being the only protein for which an export from plastids and translocation to the nucleus has been experimentally demonstrated. Other proteins, however, strongly support the notion that this pathway might be more common than currently believed.
authors.affiliation: Department of Arctic and Marine Biology, University of Tromsø, Tromsø 9037, Norway.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Krause
authors.affiliation: Institute of Botany, University of Kiel, Olshausenstrasse 40, Kiel 24098, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Oetke
authors.affiliation: Institute of Botany, University of Kiel, Olshausenstrasse 40, Kiel 24098, Germany.
authors.forename: Karin
authors.initials: K
authors.lastname: Krupinska
mesh_terms: D029681:Arabidopsis Proteins / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics*; D002736:Chloroplasts / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics*; D010944:Plants / Q000235:genetics* / Q000378:metabolism*; D018087:Plastids / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C517860:WRKY33 protein, Arabidopsis; C503333:Whirly1 protein, Arabidopsis
keywords: WHIRLY1; chloroplasts; protein targeting; retrograde signals