PML-dependent apoptosis after DNA damage is regulated by the checkpoint kinase hCds1/Chk2
NATURE CELL BIOLOGY
2002; 4 (11): 865-870
Localization, dynamics, and protein interactions reveal distinct roles for ER and Golgi SNAREs
JOURNAL OF CELL BIOLOGY
1998; 141 (7): 1489-1502
The promyelocytic leukaemia (PML) gene is translocated in most acute promyelocytic leukaemias and encodes a tumour suppressor protein. PML is involved in multiple apoptotic pathways and is thought to be pivotal in gamma irradiation-induced apoptosis. The DNA damage checkpoint kinase hCds1/Chk2 is necessary for p53-dependent apoptosis after gamma irradiation. In addition, gamma irradiation-induced apoptosis also occurs through p53-independent mechanisms, although the molecular mechanism remains largely unknown. Here, we report that hCds1/Chk2 mediates gamma irradiation-induced apoptosis in a p53-independent manner through an ataxia telangiectasia-mutated (ATM)-hCds1/Chk2-PML pathway. Our results provide the first evidence of a functional relationship between PML and a checkpoint kinase in gamma irradiation-induced apoptosis.
View details for DOI 10.1038/ncb869
View details for Web of Science ID 000179137700015
View details for PubMedID 12402044
Protein interactions regulating vesicle transport between the endoplasmic reticulum and Golgi apparatus in mammalian cells
1997; 89 (1): 149-158
ER-to-Golgi transport, and perhaps intraGolgi transport involves a set of interacting soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins including syntaxin 5, GOS-28, membrin, rsec22b, and rbet1. By immunoelectron microscopy we find that rsec22b and rbet1 are enriched in COPII-coated vesicles that bud from the ER and presumably fuse with nearby vesicular tubular clusters (VTCs). However, all of the SNAREs were found on both COPII- and COPI-coated membranes, indicating that similar SNARE machinery directs both vesicle pathways. rsec22b and rbet1 do not appear beyond the first Golgi cisterna, whereas syntaxin 5 and membrin penetrate deeply into the Golgi stacks. Temperature shifts reveal that membrin, rsec22b, rbet1, and syntaxin 5 are present together on membranes that rapidly recycle between peripheral and Golgi-centric locations. GOS-28, on the other hand, maintains a fixed localization in the Golgi. By immunoprecipitation analysis, syntaxin 5 exists in at least two major subcomplexes: one containing syntaxin 5 (34-kD isoform) and GOS-28, and another containing syntaxin 5 (41- and 34-kD isoforms), membrin, rsec22b, and rbet1. Both subcomplexes appear to involve direct interactions of each SNARE with syntaxin 5. Our results indicate a central role for complexes among rbet1, rsec22b, membrin, and syntaxin 5 (34 and 41 kD) at two membrane fusion interfaces: the fusion of ER-derived vesicles with VTCs, and the assembly of VTCs to form cis-Golgi elements. The 34-kD syntaxin 5 isoform, membrin, and GOS-28 may function in intraGolgi transport.
View details for Web of Science ID 000074605300002
View details for PubMedID 9647643
The proposed cis-Golgi vesicle receptor syntaxin 5 was found in a complex with Golgi-associated SNARE of 28 kDa (GOS-28), rbet1, rsly1, and two novel proteins characterized herein: rat sec22b and membrin, both cytoplasmically oriented integral membrane proteins. The complex appears to recapitulate vesicle docking interactions of proteins originating from distinct compartments, since syntaxin 5, rbet1, and GOS-28 localize to Golgi membranes, whereas mouse sec22b and membrin accumulate in the endoplasmic reticulum. Protein interactions in the complex are dramatically rearranged by N-ethylmaleimide-sensitive factor. The complex consists of two or more subcomplexes with some members (rat sec22b and syntaxin 5) in common and others (rbet1 and GOS-28) mutually exclusively associated. We propose that these protein interactions determine vesicle docking/fusion fidelity between the endoplasmic reticulum and Golgi.
View details for Web of Science ID A1997WR68500018
View details for PubMedID 9094723