Niimi T, Kumagai C, Okano M, Kitagawa Y
Graduate Program for Biochemical Regulation, Graduate School of Agricultural Sciences, Nagoya University, Japan.
Matrix Biol. 1997 Oct;16(4):223-30. doi: 10.1016/s0945-053x(97)90011-1.
We report that laminin-8 (alpha 4 beta 1 gamma 1) is the specific isoform of laminin synthesized in adipocytes. Reverse transcription-polymerase chain reaction (RT-PCR) of mRNA from mouse 3T3-L1 cells with paired primers for alpha 1, alpha 2, alpha 3, alpha 4, alpha 5, beta 1, beta 2, beta 3, gamma 1 and gamma 2 laminins yielded amplified fragments only for alpha 4, beta 1 and gamma 1. A polyclonal antibody against mouse laminin-1 (alpha 1 beta 1 gamma 1) precipitated alpha 4 in addition to beta 1 and gamma 1, while the antibody against a deduced peptide sequence of mouse alpha 4 in addition to beta 1 and gamma 1 in addition to alpha 4. Thus, laminin-8 (alpha 4 beta 1 gamma 1) is the only isoform expressed in 3T3-L1 cells. Northern blots showed that the levels of alpha 4, beta 1 and gamma 1 mRNAs increased 2.5-fold during adipose conversion of 3T3-L1 cells. A 1062 bp cDNA fragment cloned by RT-PCR demonstrated a polymorphism in the mouse alpha 4 gene which would lead to five amino acid changes in the domain G.
我们报告层粘连蛋白-8（α4β1γ1）是脂肪细胞中合成的层粘连蛋白的特定异构体。用针对α1、α2、α3、α4、α5、β1、β2、β3、γ1和γ2层粘连蛋白的配对引物对小鼠3T3-L1细胞的mRNA进行逆转录-聚合酶链反应（RT-PCR），仅产生了α4、β1和γ1的扩增片段。一种针对小鼠层粘连蛋白-1（α1β1γ1）的多克隆抗体除了沉淀β1和γ1外，还沉淀了α4，而针对小鼠α4推导肽序列的抗体除了沉淀β1和γ1外，还沉淀了α4。因此，层粘连蛋白-8（α4β1γ1）是3T3-L1细胞中表达的唯一异构体。Northern印迹显示，在3T3-L1细胞脂肪转化过程中，α4、β1和γ1 mRNA的水平增加了2.5倍。通过RT-PCR克隆的一个1062 bp cDNA片段显示小鼠α4基因存在多态性，这将导致结构域G中有五个氨基酸发生变化。
