Two novel heteropolymer-forming proteins maintain the multicellular shape of the cyanobacterium Anabaena sp. PCC 7120
Two novel heteropolymer-forming proteins maintain the multicellular shape of the cyanobacterium Anabaena sp. PCC 7120
复制标题
两种新型杂聚物形成蛋白维持了蓝藻鱼腥藻的多细胞形状。
DOI：
10.1111/febs.15630
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Springstein B
中科院分区：
文献类型：
--
作者：
Springstein B
Polymerizing and filament‐forming proteins are instrumental for numerous cellular processes such as cell division and growth. Their function in stabilization and localization of protein complexes and replicons is achieved by a filamentous structure. Known filamentous proteins assemble into homopolymers consisting of single subunits – for example, MreB and FtsZ in bacteria – or heteropolymers that are composed of two subunits, for example, keratin and α/β tubulin in eukaryotes. Here, we describe two novel coiled‐coil‐rich proteins (CCRPs) in the filament‐forming cyanobacteriumAnabaenasp. PCC 7120 (hereafterAnabaena) that assemble into a heteropolymer and function in the maintenance of theAnabaenamulticellular shape (termed trichome). The two CCRPs – Alr4504 and Alr4505 (named ZicK and ZacK) – are strictly interdependent for the assembly of protein filamentsin vivoand polymerize nucleotide independentlyin vitro, similar to known intermediate filament (IF) proteins. A ΔzicKΔzacKdouble mutant is characterized by a zigzagged cell arrangement and hence a loss of the typical linearAnabaenatrichome shape. ZicK and ZacK interact with themselves, with each other, with the elongasome protein MreB, the septal junction protein SepJ and the divisome associate septal protein SepI. Our results suggest that ZicK and ZacK function in cooperation with SepJ and MreB to stabilize theAnabaenatrichome and are likely essential for the manifestation of the multicellular shape inAnabaena. Our study reveals the presence of filament‐forming IF‐like proteins whose function is achieved through the formation of heteropolymers in cyanobacteria.
