scholarly journals Structural model for the organization of the transmembrane spans of the human red-cell anion exchanger (band 3; AE1)

1999 ◽  
Vol 344 (3) ◽  
pp. 699 ◽  
Author(s):  
Jonathan D. GROVES ◽  
Michael J.A. TANNER
2016 ◽  
Vol 1858 (7) ◽  
pp. 1507-1532 ◽  
Author(s):  
Reinhart A.F. Reithmeier ◽  
Joseph R. Casey ◽  
Antreas C. Kalli ◽  
Mark S.P. Sansom ◽  
Yilmaz Alguel ◽  
...  

1994 ◽  
Vol 1 ◽  
pp. 235
Author(s):  
Mutsumi Inaba ◽  
Miyuki Takeuchi ◽  
Kota Sato ◽  
Ken-ichiro Ono ◽  
Yoshimitsu Maede
Keyword(s):  
Band 3 ◽  

1999 ◽  
Vol 27 (6) ◽  
pp. 917-923 ◽  
Author(s):  
Jonathan D. Groves ◽  
Mark D. Parker ◽  
David Askin ◽  
Pierre Falson ◽  
Marc le Maire ◽  
...  

1999 ◽  
Vol 344 (3) ◽  
pp. 699-711 ◽  
Author(s):  
Jonathan D. GROVES ◽  
Michael J. A. TANNER

We have examined the functional co-assembly of non-complementary pairs of N- and C-terminal polypeptide fragments of the anion transport domain (b3mem) of human red-cell band 3. cDNA clones encoding non-contiguous pairs of fragments with one transmembrane (TM) region omitted, or overlapping pairs of fragments with between one and ten TM regions duplicated, were co-expressed in Xenopus oocytes and a cell-free translation system. Stilbene disulphonate-sensitive chloride uptake assays in oocytes revealed that the omission of any single TM region of b3mem except spans 6 and 7 caused a complete loss of functional expression. In contrast, co-expressed pairs of fragments overlapping a single TM region 5, 6, 7, 8, 9-10 or 11-12 retained a high level of functionality, whereas fragments overlapping the clusters of TM regions 2-5, 4-5, 5-8 and 8-10 also mediated some stilbene disulphonate-sensitive uptake. The co-assembly of N- or C-terminal fragments with intact band 3, b3mem or other fragments was examined by co-immunoprecipitation in non-denaturing detergent solutions by using monoclonal antibodies against the termini of b3mem. All the fragments, except for TM spans 13-14, co-immunoprecipitated with b3mem. The medium-sized N-terminal fragments comprising spans 1-6, 1-7 or 1-8 co-immunoprecipitated particularly strongly with the C-terminal fragments containing spans 8-14 or 9-14. The fragments comprising spans 1-4 or 1-12 co-immunoprecipitated less extensively than the other N-terminal fragments with either b3mem or C-terminal fragments. There is sufficient flexibility in the structure of b3mem to allow the inclusion of at least one duplicated TM span without a loss of function. We propose a working model for the organization of TM spans of dimeric band 3 based on current evidence.


1999 ◽  
Vol 285 (3) ◽  
pp. 1289-1307 ◽  
Author(s):  
Eric J. Chambers ◽  
Graham B. Bloomberg ◽  
Susan M. Ring ◽  
Michael J.A. Tanner

1999 ◽  
Vol 344 (3) ◽  
pp. 687-697 ◽  
Author(s):  
Jonathan D. GROVES ◽  
Michael J. A. TANNER

The red-cell anion exchanger (band 3; AE1) is a multispanning membrane protein that traverses the bilayer up to 14 times and is N-glycosylated at Asn-642. We have shown that the integrity of six different loops are not essential for stilbene disulphonate-sensitive chloride uptake in Xenopus oocytes. We used an N-glycosylation mutagenesis approach to examine the orientation of the N-terminus and the endogenous glycosylation site of each C-terminal fragment by cell-free translation. The fragments initiating in the loops preceding spans 2, 9 and 11 did not insert into the membrane with the expected orientation. Furthermore, N-glycosylation of Asn-642 might facilitate the membrane integration of span 7. The correct integration of spans 2-3 required the presence of the region containing span 4 and that the luminal exposure of the C-terminus of span 7 is increased in the presence of the region including span 6 or span 8. The results suggest the span 8 region is required for the correct folding of spans 9-10, at least in the presence of the span 11-12 region. Our results suggest that there are intramolecular interactions between the regions of transmembrane spans 1 and 2, 2 and 4, 4 and 5, 7 and 8, 8 and 9-10, and 9-10 and 11-12. Spans 1, 4, 5, 6 and 8 might act as a scaffold for the assembly of spans 2-3, 7 and 9-10. This approach might provide a general method for dissecting the interactions between membrane-spanning regions of polytopic membrane proteins.


1997 ◽  
Vol 100 (7) ◽  
pp. 1693-1707 ◽  
Author(s):  
L J Bruce ◽  
D L Cope ◽  
G K Jones ◽  
A E Schofield ◽  
M Burley ◽  
...  

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