Tic32, an essential component in chloroplast biogenesis

被引:86
作者
Hörmann, F
Küchler, M
Sveshnikov, D
Oppermann, U
Li, Y
Soll, J
机构
[1] Univ Munich, Dept Biol & Plant Biochem, D-80638 Munich, Germany
[2] Karolinska Inst, Dept Med Biochem & Biophys, S-17177 Stockholm, Sweden
[3] Max Planck Inst Plant Breeding, D-50829 Cologne, Germany
关键词
D O I
10.1074/jbc.M402817200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Chloroplast protein import across the inner envelope is facilitated by the translocon of the inner envelope of chloroplasts (Tic). Here we have identified Tic32 as a novel subunit of the Tic complex. Tic32 can be purified from solubilized inner envelope membranes by chromatography on Tic110 containing affinity matrix. Co-immunoprecipitation experiments using either Tic32 or Tic110 antisera indicated a tight association between these polypeptides as well as with other Tic subunits, e. g. Tic40, Tic22, or Tic62, whereas the outer envelope protein Toc75 was not found in this complex. Chemical cross-linking suggests that Tic32 is involved late in the overall translocation process, because both the precursor form as well as the mature form of Rubisco small subunit can be detected. We were unable to isolate Arabidopsis null mutants of the attic32 gene, indicating that Tic32 is essential for viability. Deletion of the attic32 gene resulted in early seed abortion because the embryo was unable to differentiate from the heart stage to the torpedo stage. The homology of Tic32 to short-chain dehydrogenases suggests a dual role of Tic32 in import, one as a regulatory component and one as an important subunit in the assembly of the entire complex.
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收藏
页码:34756 / 34762
页数:7
相关论文
共 61 条
[31]   Protein import into chloroplasts involves redox-regulated proteins [J].
Küchler, M ;
Decker, S ;
Hörmann, F ;
Soll, J ;
Heins, L .
EMBO JOURNAL, 2002, 21 (22) :6136-6145
[32]   The titan mutants of Arabidopsis are disrupted in mitosis and cell cycle control during seed development [J].
Liu, CM ;
Meinke, DW .
PLANT JOURNAL, 1998, 16 (01) :21-31
[33]   A nuclear-coded chloroplastic inner envelope membrane protein uses a soluble sorting intermediate upon import into the organelle [J].
Lubeck, J ;
Heins, L ;
Soll, J .
JOURNAL OF CELL BIOLOGY, 1997, 137 (06) :1279-1286
[34]   Topology of IEP110, a component of the chloroplastic protein import machinery present in the inner envelope membrane [J].
Lubeck, J ;
Soll, J ;
Akita, M ;
Nielsen, E ;
Keegstra, K .
EMBO JOURNAL, 1996, 15 (16) :4230-4238
[35]   A REVISED MEDIUM FOR RAPID GROWTH AND BIO ASSAYS WITH TOBACCO TISSUE CULTURES [J].
MURASHIGE, T ;
SKOOG, F .
PHYSIOLOGIA PLANTARUM, 1962, 15 (03) :473-497
[36]  
NADA A, 2004, IN PRESS J CELL SCI
[37]   Stable association of chloroplastic precursors with protein translocation complexes that contain proteins from both envelope membranes and a stromal Hsp 100 molecular chaperone [J].
Nielsen, E ;
Akita, M ;
DavilaAponte, J ;
Keegstra, K .
EMBO JOURNAL, 1997, 16 (05) :935-946
[38]   IDENTIFICATION OF 2 STRUCTURALLY RELATED PROTEINS INVOLVED IN PROTEOLYTIC PROCESSING OF PRECURSORS TARGETED TO THE CHLOROPLAST [J].
OBLONG, JE ;
LAMPPA, GK .
EMBO JOURNAL, 1992, 11 (12) :4401-4409
[39]  
OLSEN LJ, 1989, J BIOL CHEM, V264, P6724
[40]   Short-chain dehydrogenases/reductases (SDR): the 2002 update [J].
Oppermann, U ;
Filling, C ;
Hult, M ;
Shafqat, N ;
Wu, XQ ;
Lindh, M ;
Shafqat, J ;
Nordling, E ;
Kallberg, Y ;
Persson, B ;
Jornvall, H .
CHEMICO-BIOLOGICAL INTERACTIONS, 2003, 143 :247-253