Iron deficiency influences NtcA‐dependent regulation of fatty acid desaturation and heterocyte envelop formation in Anabaena sp. PCC 7120

Abstract

In Anabaena sp. PCC 7120, iron is an essential trace element and its availability determines proper functioning of several kinds of metabolisms. Iron deficiency leads to several unavoidable consequences including membrane damage. In the present study, we dealt with the impact of iron deficiency on NtcA (global nitrogen regulator)-dependent regulation of two important processes, i.e. fatty acid desaturation and heterocyte envelop formation in cyanobacterium Anabaena sp. PCC 7120. In Anabaena sp. PCC 7120, NtcA regulates fatty acid desaturation by regulating enzyme fatty acid desaturases. The NtcA-based regulation of fatty acid desaturation may be direct or indirect. Furthermore, the expression of genes involved in the heterocyte envelope polysaccharide (HEP) layer formation (hepABCK) and heterocyte-specific glycolipids (HGLs) synthesis (devH, hglE , prpJ and devB) were also under the control of NtcA and reduced under iron deficiency background. The enhanced expression of furA and early downregulation of ntcA under iron deficiency is responsible for reduction in fatty acid desaturation as well as decrease in the expression of genes involved in HEP layer formation and HGL synthesis. Overall results confirmed that iron deficiency influences the NtcA-based regulation of fatty acid desaturation and heterocyte envelop formation in Anabaena sp. PCC 7120.

FurC (PerR) from Anabaena sp. PCC7120: a versatile transcriptional regulator engaged in the regulatory network of heterocyst development and nitrogen fixation

“…There are increasing evidences of the interplay between iron deficiency, oxidative stress and nitrogen metabolism (Latifi et al, 2005;Saxena et al, 2006;Kaushik et al, 2015;Kaushik et al, 2017;Kaushik and Mishra, 2019;Pernil and Schleiff, 2019;Robles-Rengel et al, 2019). Therefore, a protein like PerR that integrates the levels of iron, manganese and hydrogen peroxide in the cell can display an important role in this cross-regulation.…”

“…Likewise, it has been demonstrated that iron deficiency influences the regulation exerted by NtcA on genes involved in fatty acid desaturation and heterocyst envelope formation in Anabaena sp. PCC7120 (Kaushik and Mishra, 2019). Recently, Robles-Rengel et al…”

“…Likewise, it has been demonstrated that iron deficiency influences the regulation exerted by NtcA on genes involved in fatty acid desaturation and heterocyst envelope formation in Anabaena sp. PCC7120 (Kaushik and Mishra, 2019). Recently, Robles-Rengel et al (2019), described that hydrogen peroxide alters the expression of some genes related to nitrogen metabolism and interestingly revealed that H 2 O 2 presence diminishes 2-OG levels in the cell.…”

“…It is well known that in Anabaena sp. PCC7120 under nitrogendeprived conditions, the demand for iron increases (Saxena et al, 2006;Kaushik and Mishra, 2019) and subsequently, iron deficiency can lead to oxidative stress (Latifi et al, 2005;Kaushik et al, 2015;Kaushik et al, 2017). Likewise, it has been demonstrated that iron deficiency influences the regulation exerted by NtcA on genes involved in fatty acid desaturation and heterocyst envelope formation in Anabaena sp.…”

The tale of caspase homologues and their evolutionary outlook: deciphering programmed cell death in cyanobacteria

“…2 ). Although, vacuolation had already been reported in cyanobacteria upon ageing ( Echlin, 1964 ; Lang and Rae, 1967 ; Peat and Whitton, 1967 ; Miller and Lang, 1971 ; Ermakova et al , 1977 ), heat shock ( Findley et al , 1970 ), and heterocyte differentiation ( Findley et al , 1970 ; Kulasooriya et al , 1972 ; Wilcox et al , 1973 ; Roussard Jacquemin, 1983 ; Wolk et al , 1994 ; Mishra et al , 2018 ; Kaushik and Mishra, 2019 ), the exact reasons behind this are still unknown. Nevertheless, based on these observations the existence of a more complicated and conjoint mechanism leading to two opposite fates, cell death and heterocyte differentiation, can be speculated upon.…”