The supramolecular architecture of junctional microdomains in native lens membranes

被引:82
作者
Buzhynskyy, Nikolay
Hite, Richard K.
Walz, Thomas
Scheuring, Simon
机构
[1] Inst Curie, CNRS, UMR168, F-75248 Paris, France
[2] Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA
关键词
aquaporin; atomic force microscopy; connexin; gap junction; membrane protein;
D O I
10.1038/sj.embor.7400858
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
Gap junctions formed by connexons and thin junctions formed by lens-specific aquaporin 0 (AQP0) mediate the tight packing of fibre cells necessary for lens transparency. Gap junctions conduct water, ions and metabolites between cells, whereas junctional AQP0 seems to be involved in cell adhesion. High-resolution atomic force microscopy (AFM) showed the supramolecular organization of these proteins in native lens core membranes, in which AQP0 forms two-dimensional arrays that are surrounded by densely packed gap junction channels. These junctional microdomains simultaneously provide adhesion and communication between fibre cells. The AFM topographs also showed that the extracellular loops of AQP0 in junctional microdomains adopt a conformation that closely resembles the structure of junctional AQP0, in which the water pore is thought to be closed. Finally, time-lapse AFM imaging provided insights into AQP0 array formation. This first high-resolution view of a multicomponent eukaryotic membrane shows how membrane proteins self-assemble into functional microdomains.
引用
收藏
页码:51 / 55
页数:5
相关论文
共 27 条
[1]   Aquaporin water channels [J].
Agre, P .
BIOSCIENCE REPORTS, 2004, 24 (03) :127-163
[2]   PROTEIN COMPOSITION OF BOVINE LENS CORTICAL FIBER CELL-MEMBRANES [J].
ALCALA, J ;
LIESKA, N ;
MAISEL, H .
EXPERIMENTAL EYE RESEARCH, 1975, 21 (06) :581-595
[3]   Comparison of the water transporting properties of MIP and AQP1 [J].
Chandy, G ;
Zampighi, GA ;
Kreman, M ;
Hall, JE .
JOURNAL OF MEMBRANE BIOLOGY, 1997, 159 (01) :29-39
[4]  
Donaldson P, 2001, NEWS PHYSIOL SCI, V16, P118
[5]   A Cα model for the transmembrane α helices of gap junction intercellular channels [J].
Fleishman, SJ ;
Unger, VM ;
Yeager, M ;
Ben-Tal, N .
MOLECULAR CELL, 2004, 15 (06) :879-888
[6]  
FLESCHNER CR, 1991, J LIPID RES, V32, P45
[7]   Surface tongue-and-groove contours on lens MIP facilitate cell-to-cell adherence [J].
Fotiadis, D ;
Hasler, L ;
Müller, DJ ;
Stahlberg, H ;
Kistler, J ;
Engel, A .
JOURNAL OF MOLECULAR BIOLOGY, 2000, 300 (04) :779-789
[8]   Temperature dependence of the surface topography in dimyristoylphosphatidylcholine/distearoylphosphatidylcholine multibilayers [J].
Giocondi, MC ;
Le Grimellec, C .
BIOPHYSICAL JOURNAL, 2004, 86 (04) :2218-2230
[9]   Aquaporin-0 membrane junctions form upon proteolytic cleavage [J].
Gonen, T ;
Cheng, Y ;
Kistler, J ;
Walz, T .
JOURNAL OF MOLECULAR BIOLOGY, 2004, 342 (04) :1337-1345
[10]   Aquaporin-0 membrane junctions reveal the structure of a closed water pore [J].
Gonen, T ;
Sliz, P ;
Kistler, J ;
Cheng, YF ;
Walz, T .
NATURE, 2004, 429 (6988) :193-197