Li Bin, Huang Xu, Zhao Jindong
College of Life Sciences, Peking University, Beijing, PR China.
FEBS Lett. 2002 Apr 24;517(1-3):87-91. doi: 10.1016/s0014-5793(02)02582-6.
The hetN gene plays an important role in heterocyst differentiation and pattern formation. An immunoblotting study showed that the hetN gene in Anabaena sp. PCC 7120 was expressed in vegetative cells grown with combined nitrogen. After a switch to a medium without combined nitrogen, hetN expression first declined and was then followed by a rapid increase in its product, HetN, which was only present in mature heterocysts. HetN is located on both thylakoid membranes and plasma membranes as determined by immunoblotting using purified membranes. Overexpression of hetN completely prevented hetR up-regulation under nitrogen-deprivation conditions, suggesting that its role in pattern control may depend on its inhibition of hetR expression.
hetN基因在异形胞分化和模式形成中发挥着重要作用。一项免疫印迹研究表明，鱼腥藻PCC 7120中的hetN基因在含有化合态氮的营养细胞中表达。在转换到不含化合态氮的培养基后，hetN的表达首先下降，随后其产物HetN迅速增加，而HetN仅存在于成熟异形胞中。通过使用纯化膜进行免疫印迹测定，发现HetN位于类囊体膜和质膜上。在氮缺乏条件下，hetN的过表达完全阻止了hetR的上调，这表明它在模式控制中的作用可能取决于对hetR表达的抑制。
