REGULAR ARTICLES
Cell Research (1996)6:11-22
© 1996
SIBS, CAS All rights reserved 1001-0602/96
Assemly of lamins in vitro
MIN GUNG WEI,XIANG JUN TONG, BIN CHEN, BO ZHANG,ZHONG FAN LIU MING XIAODING,ZHONG
HE ZHAI
College of Life and Molecular Engineering, Peking University Beijing
100871,China
After lamins A,B and C were isolated and pirofoed from rat liver, their
assembly properties were examined by electron microscopy and scanning tunneling
microscopy using negative staining and the plycerol coating method, respectively.
By varying the assembly time or the ionic conditions under shich polymerization
takes place , we have observed different stages of lamin assembly, which
may provide clues on the structure of the 10 nm lamin filaments. At the
first level of stucture organization , two lamin polypeptides associate
laterally into dimers with the two domains being paralled and in register
,. At the second level of structure organization , two dimers associate
in a half-staggered and antiparallel fashion to form a tetramer 75 nm in
length . At the third level of structural organization , 4-10 lamin tetramers
associate laterally in register to form 75 nm long 10 nm filaments , which
in turn combine head to head into long , fully assmenled lamin filaments.
The assembled lamin filaments are nonpolar.
Keywords : Nuclear lamina , lamins, scanning tunneling microscopy,
assembly. |
