Talk:XBP1

Jargon
Can someone please rewrite this or add explanations so that non-biochemists may also understand the article? De728631 (talk) 14:43, 14 September 2008 (UTC)

XBP1: location of IRE1-mediated splicing and interaction with FoxO1
"Because the lumen of the ER is continuous with the perinuclear space, the activated ribonuclease domains can penetrate the inner leaflet of the nuclear envelope. Within the nucleus, activated IRE1 catalyses the excision of a 26 nucleotide unconventional intron from XBP-1 mRNA, in a manner mechanistically similar to pre-tRNA splicing."

--- is this correct?

Most review articles seem to indicate that the place of IRE1-mediated XBP1 splicing is not the nucleus but the cytoplasm. I am unable to find any articles with original data that can pinpoint the site of XBP1 mRNA cleavage. In yeast, the tRNA ligase responsible for stitching spliced HAC1 mRNA fragments together is located in the nucleus and hence it seems reasonable that splicing of HAC1 should occur in the nucleus "Mechanism of non-spliceosomal mRNA splicing in the unfolded protein response pathway. Gonzalez TN, Sidrauski C, Dörfler S, Walter P. EMBO J. 1999 Jun 1;18(11):3119-32.", but this article is about XBP1 - and the ligase for XBP1 remains unknown.... "An intact unfolded protein response in Trpt1 knockout mice reveals phylogenic divergence in pathways for RNA ligation. Harding HP, Lackey JG, Hsu HC, Zhang Y, Deng J, Xu RM, Damha MJ, Ron D. RNA. 2008 Feb;14(2):225-32. Epub 2007 Dec 19."

In addition, it was recently shown that XBP1(s) interacts with the transcription factor FoxO1. Is this worth mentioning - given FoxO1's role in B cell development and glucose homeostasis? "Regulation of glucose homeostasis through a XBP-1-FoxO1 interaction. Zhou Y, Lee J, Reno CM, Sun C, Park SW, Chung J, Lee J, Fisher SJ, White MF, Biddinger SB, Ozcan U. Nat Med. 2011 Mar;17(3):356-65. Epub 2011 Feb 13."

Aphetoros (talk) 23:22, 27 August 2011 (UTC)