Gene Expression during Heterocyst Differentiation

摘要: Abstract Some cyanobacteria (oxygenic phototrophs) grow as chains of vegetative cells (filaments or trichomes). When placed in media lacking combined nitrogen, some the filaments differentiate into N2-fixing heterocysts. The nitrogen fixation system is inactivated by oxygen, and heterocyst provides a micro-oxic environment for nitrogenase to function. In this review, we first describe special envelope metabolism that makes micro-oxic, concentrate then on regulation gene expression during process differentiation. Differentiation starts response persistent high cellular carbon-to-nitrogen balance signalled 2-oxoglutarate, which results activation global transcriptional regulator NtcA followed increased expression, mainly localized differentiating cells, hetR (encoding differentiation-specific transcription factor HetR) ntcA genes. genes encoding proteins transform cell activated with spatiotemporal specificity produce mature functional heterocyst. Recent analyses have added information time course levels differentiation, much also available promoters number these Contiguous building complex promoter regions are common among heterocyst-related Understanding molecular mechanism operation promoters, including roles HetR NtcA, major goal research field.