Dissection of Membrane Dynamics of the ARF‐Guanine Nucleotide Exchange Factor GBF1

Traffic - Tập 6 Số 5 - Trang 374-385 - 2005
Tomasz Szul1, Rafael García‐Mata1,2, Elizabeth Brandon1, Svetlana A. Shestopal1, Cecilia Álvarez1,3, Elizabeth Sztul1
1Department of Cell Biology, University of Alabama at Birmingham, Birmingham, AL 35924, USA
2Present address: Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, NC 27599, USA.
3Present address: Dpto. de Bioquimica Clinica, Fac. Ciencias Quimicas, Ciudad Universitaria, Cordoba CP.5000, Argentina.

Tóm tắt

ADP‐ribosylation factor (ARF)‐facilitated recruitment of COP I to membranes is required for secretory traffic. The guanine nucleotide exchange factor GBF1 activates ARF and regulates ARF/COP I dynamics at the endoplasmic reticulum (ER)–Golgi interface. Like ARF and coatomer, GBF1 peripherally associates with membranes. ADP‐ribosylation factor and coatomer have been shown to rapidly cycle between membranes and cytosol, but the membrane dynamics of GBF1 are unknown. Here, we used fluorescence recovery after photobleaching to characterize the behavior of GFP‐tagged GBF1. We report that GBF1 rapidly cycles between membranes and the cytosol (t1/2 is approximately 17 ± 1 seconds). GBF1 cycles faster than GFP‐tagged ARF, suggesting that in each round of association/dissociation, GBF1 catalyzes a single event of ARF activation, and that the activated ARF remains on membrane after GBF1 dissociation. Using three different approaches [expression of an inactive (E794K) GBF1 mutant, expression of the ARF1 (T31N) mutant with decreased affinity for GTP and Brefeldin A treatment], we show that GBF1 is stabilized on membranes when in a complex with ARF–GDP. GBF1 dissociation from ARF and membranes is triggered by its catalytic activity, i.e. the displacement of GDP and the subsequent binding of GTP to ARF. Our findings imply that continuous cycles of recruitment and dissociation of GBF1 to membranes are required for sustained ARF activation and COP I recruitment that underlies ER‐Golgi traffic.

Từ khóa


Tài liệu tham khảo

10.1034/j.1600-0854.2000.010501.x

10.1016/S0955-0674(03)00071-1

10.1016/S0955-0674(00)00119-8

10.1007/s004180050247

10.1038/360350a0

10.1091/mbc.11.4.1241

10.1016/S0962-8924(99)01699-2

10.1091/mbc.e03-06-0443

10.1091/mbc.E02-11-0730

10.1083/jcb.146.1.71

10.1091/mbc.01-08-0420

10.1034/j.1600-0854.2002.30705.x

10.1091/mbc.E02-10-0693

10.1242/jcs.111.9.1277

10.1038/sj.embor.embor942

10.1038/417187a

10.1091/mbc.11.9.3013

10.1083/jcb.143.6.1505

10.1091/mbc.7.4.631

10.1083/jcb.200107045

10.1093/emboj/17.13.3651

10.1083/jcb.128.6.1003

10.1016/S0021-9258(17)42277-0

10.1093/emboj/20.23.6751

10.1083/jcb.124.3.289

10.1074/jbc.272.49.30848

10.1074/jbc.270.3.1337

10.1016/S0021-9258(18)42378-2

10.1038/sj.embor.embor762

10.1016/0092-8674(89)90685-5

10.1083/jcb.116.5.1071

10.1242/jcs.113.1.135

10.1016/S0092-8674(00)80379-7

10.1016/S0960-9822(99)80365-0

10.1083/jcb.124.4.415

10.1073/pnas.94.9.4418

10.1074/jbc.274.20.14198

10.1038/nature02197

10.1016/S0092-8674(00)80933-2

10.1016/S0092-8674(00)81754-7

10.1016/S1097-2765(03)00475-1

10.1016/S1097-2765(00)80455-4

10.1073/pnas.170290597

10.1074/jbc.M112427200

10.1242/jcs.114.12.2241

10.1038/384479a0

10.1091/mbc.E04-07-0599

10.1242/jcs.00896

10.1083/jcb.146.2.285

10.1074/jbc.273.50.33825

10.1083/jcb.123.6.1365

Honda A, 2004, Membrin, an ER‐Golgi SNARE, is an Arf1 receptor, Mol Biol Cell, 15, 189a

Thông tin
Thông tin xuất bản

Traffic

Tập 6 Số 5

374-385

Thông tin tác giả