Distinct roles of mouse laminin β1 long arm domains for α1β1γ1 trimer formation

FEBS Letters

Kitagawa, Yasuo¹  Niimi, Tomoaki¹ 

[1] Graduate Program of Biochemical Regulation, School of Agricultural Sciences, Nagoya University, Nagoya 464-01, Japan

关键词: Laminin;    Heptad repeat;    Disulfide-bonding;   

DOI  :  10.1016/S0014-5793(96)01355-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Mouse embryonal carcinoma F9 cells expressing partial mouse laminin β1 covering either the C-terminal end (Δβ1S) or the whole (Δβ1L) of the long arm were established to study the assembly and interchain disulfide-bonding of β1 to endogenous laminin α1 and γ1. Both Δβ1S and Δβ1L were disulfide-bonded to γ1 but only Δβ1Lγ1 dimer formed a disulfide-bonded α1Δβ1Lγ1 trimer which was actively secreted into the medium. Meanwhile, in the cells producing Δβ1Sγ1 dimer, the level of endogenous α1β1γ1 was reduced but the level of monomeric α1 was increased, suggesting that α1 was recruited to trimer formation with the Δβ1Sγ1 dimer without disulfide-bonding. This shows that the Δβ1Sγ1 dimer can associate with α1 but not support the disulfide-bonding at the N-terminus of the long arm of α1. While control cells secrete neither monomeric α1 nor the β1γ1 dimer into the medium, the Δβ1Sγ1 producing cells probably do as α1Δβ1γ1 trimer. We thus propose that the N- and C-termini of the long arm of laminin β1 have distinct roles for trimer formation.

【 授权许可】

Unknown