title: Dynamic trafficking of wheat γ-gliadin and of its structural domains in tobacco cells, studied with fluorescent protein fusions.
abstract: Prolamins, the main storage proteins of wheat seeds, are synthesized and retained in the endoplasmic reticulum (ER) of the endosperm cells, where they accumulate in protein bodies (PBs) and are then exported to the storage vacuole. The mechanisms leading to these events are unresolved. To investigate this unconventional trafficking pathway, wheat γ-gliadin and its isolated repeated N-terminal and cysteine-rich C-terminal domains were fused to fluorescent proteins and expressed in tobacco leaf epidermal cells. The results indicated that γ-gliadin and both isolated domains were able to be retained and accumulated as protein body-like structures (PBLS) in the ER, suggesting that tandem repeats are not the only sequence involved in γ-gliadin ER retention and PBLS formation. The high actin-dependent mobility of γ-gliadin PBLS is also reported, and it is demonstrated that most of them do not co-localize with Golgi body or pre-vacuolar compartment markers. Both γ-gliadin domains are found in the same PBLS when co-expressed, which is most probably due to their ability to interact with each other, as indicated by the yeast two-hybrid and FRET-FLIM experiments. Moreover, when stably expressed in BY-2 cells, green fluorescent protein (GFP) fusions to γ-gliadin and its isolated domains were retained in the ER for several days before being exported to the vacuole in a Golgi-dependent manner, and degraded, leading to the release of the GFP 'core'. Taken together, the results show that tobacco cells are a convenient model to study the atypical wheat prolamin trafficking with fluorescent protein fusions.
authors: UR1268 Biopolymères Interactions Assemblages, INRA, BP71627 Nantes cedex 03, France. allami@nantes.inra.fr
authors: Mathilde
authors: M
authors: Francin-Allami
authors: Amélie
authors: A
authors: Saumonneau
authors: Laurence
authors: L
authors: Lavenant
authors: Axelle
authors: A
authors: Bouder
authors: Imogen
authors: I
authors: Sparkes
authors: Chris
authors: C
authors: Hawes
authors: Yves
authors: Y
authors: Popineau
references: J Exp Bot. 2009;60(3):979-91
references: 19174462
references: Biopolymers. 2009 Aug;91(8):610-22
references: 19301297
references: Plant Cell. 2009 Dec;21(12):3937-49
references: 20040535
references: Plant Cell Physiol. 1997 Apr;38(4):404-12
references: 9177027
references: Plant Physiol. 2001 Jan;125(1):115-8
references: 11154311
references: Biochem J. 2009 Sep 25;423(2):145-55
references: 19772494
references: J Exp Bot. 2002 Apr;53(370):947-58
references: 11912237
references: Biopolymers. 2004 Feb 5;73(2):258-68
references: 14755582
references: J Exp Bot. 2001 Dec;52(365):2387-8
references: 11709589
references: J Biol Chem. 1996 Aug 2;271(31):18869-74
references: 8702547
references: Plant J. 2004 Aug;39(3):393-402
references: 15255868
references: Planta. 1982 May;154(3):277-83
references: 24276072
references: Planta. 1994;192(4):512-8
references: 7764619
references: Plant Cell. 2006 Jan;18(1):198-211
references: 16339854
references: Trends Plant Sci. 2005 Jul;10(7):316-23
references: 15950520
references: Plant Cell. 1993 Apr;5(4):443-50
references: 8485403
references: Autophagy. 2006 Apr-Jun;2(2):135-7
references: 16874086
references: Plant J. 2008 Oct;56(1):169-79
references: 18643979
references: Plant Cell. 1998 May;10(5):825-36
references: 9596640
references: Plant Physiol. 1992 Jun;99(2):718-24
references: 16668945
references: Plant Cell. 2010 Apr;22(4):1333-43
references: 20424177
references: J Cell Biol. 1992 Dec;119(5):1117-28
references: 1447291
references: BMC Biol. 2009 Jan 28;7:5
references: 19175916
references: Plant Physiol. 2003 Oct;133(2):462-9
references: 14555774
references: Plant Cell. 2006 Oct;18(10):2608-21
references: 17041149
references: EMBO J. 2008 Jan 23;27(2):315-27
references: 18216874
references: Trends Plant Sci. 2005 Mar;10(3):103-5
references: 15749466
references: J Exp Bot. 2008;59(10):2815-29
references: 18540021
references: Trends Cell Biol. 1993 Dec;3(12):437-42
references: 14731890
references: Plant Cell. 1994 Dec;6(12):1911-1922
references: 12244234
references: Plant Physiol. 2004 Nov;136(3):3420-6
references: 15542495
references: J Exp Bot. 2009;60(2):615-27
references: 19129168
references: Plant Physiol. 1993 May;102(1):61-69
references: 12231798
references: Plant Cell. 1995 Jul;7(7):945-56
references: 7640527
references: Mol Plant. 2008 Nov;1(6):1067-76
references: 19825604
references: J Cell Sci. 2004 Dec 15;117(Pt 26):6377-89
references: 15561767
references: Plant Physiol. 2004 Nov;136(3):3447-56
references: 15502013
references: Plant J. 2003 Aug;35(4):545-55
references: 12904216
references: Planta. 1997 Dec;203(4):488-94
references: 9421932
references: FEBS Lett. 2008 May 14;582(11):1599-606
references: 18423406
references: Nat Protoc. 2006;1(4):2019-25
references: 17487191
references: J Cell Sci. 1992 Jun;102 ( Pt 2):261-71
references: 1383243
references: BMC Biol. 2009 Aug 07;7:48
references: 19664215