Updating Insights into the Regulatory Mechanisms of Calcineurin-Activated Transcription Factor Crz1 in Pathogenic Fungi

Abstract

Ca2+, as a second messenger in cells, enables organisms to adapt to different environmental stresses by rapidly sensing and responding to external stimuli. In recent years, the Ca2+ mediated calcium signaling pathway has been studied systematically in various mammals and fungi, indicating that the pathway is conserved among organisms. The pathway consists mainly of complex Ca2+ channel proteins, calcium pumps, Ca2+ transporters and many related proteins. Crz1, a transcription factor downstream of the calcium signaling pathway, participates in regulating cell survival, ion homeostasis, infection structure development, cell wall integrity and virulence. This review briefly summarizes the Ca2+ mediated calcium signaling pathway and regulatory roles in plant pathogenic fungi. Based on discussing the structure and localization of transcription factor Crz1, we focus on the regulatory role of Crz1 on growth and development, stress response, pathogenicity of pathogenic fungi and its regulatory mechanisms. Furthermore, we explore the cross-talk between Crz1 and other signaling pathways. Combined with the important role and pathogenic mechanism of Crz1 in fungi, the new strategies in which Crz1 may be used as a target to explore disease control in practice are also discussed.

PuCRZ1, an C2H2 transcription factor from Polyporus umbellatus, positively regulates mycelium response to osmotic stress

“…The calcium signaling pathway plays an important role in sclerotia formation and fungal resistance. The Ca 2+ -calcineurin signaling pathway is a widely conserved calcium signaling pathway in animals and fungi, which regulates life activities such as metal ion homeostasis, cell cycle, cell growth and differentiation, and cell wall synthesis ( Berridge et al, 2003 ; Yang et al, 2022 ). The CaN-CRZ1 signaling cascade in fungal cells can be activated by different external stimuli, such as high/low temperature, hypertonicity, alkalinity, oxidative stress, and others ( Yang et al, 2022 ).…”

“…The Ca 2+ -calcineurin signaling pathway is a widely conserved calcium signaling pathway in animals and fungi, which regulates life activities such as metal ion homeostasis, cell cycle, cell growth and differentiation, and cell wall synthesis ( Berridge et al, 2003 ; Yang et al, 2022 ). The CaN-CRZ1 signaling cascade in fungal cells can be activated by different external stimuli, such as high/low temperature, hypertonicity, alkalinity, oxidative stress, and others ( Yang et al, 2022 ). In fungal cells, Calcineurin responsive Zing finger transcription factor (CRZ1) was first identified in Saccharomyces cerevisiae ( Stathopoulos and Cyert, 1997 ).…”

“…In fungal cells, Calcineurin responsive Zing finger transcription factor (CRZ1) was first identified in Saccharomyces cerevisiae ( Stathopoulos and Cyert, 1997 ). Subsequently, homologs of CRZ1 gene were identified in different species ( Gupta et al, 2022 ; Yang et al, 2022 ).…”

“…All CRZ1 homologs have one or more signature C2H2 zinc finger domains, and their functions and regulatory genes differ among different species ( Gupta et al, 2022 ; Yang et al, 2022 ). Crz1- regulated genes are involved in sclerotia formation in Verticillium dahliae ( Xiong et al, 2015 ) and Valsa pyri ( He et al, 2016 ), impaired mycelium growth and abnormal branching in Botrytis cinerea ( Schumacher et al, 2008 ), spores and conidia produced in B. cinerea , Metarhizium acridum ( Chen et al, 2017 ) and Fusarium graminearum ( Chen et al, 2019 ), morphological transformation, irregular plasma membrane structure and abnormal organelles in Candida lusitaniae ( Zhang et al, 2012 ).…”

“…The CRZ1 deletion mutants showed different responses to ion stress in different fungi ( Yang et al, 2022 ), i.e., sensitive to Na + , Li + , Mn 2+ , and Ca 2+ in B. cinerea , to only Mn 2+ in Aspergillus fumigatus , and insensitive to Na + , Li + , and Mn 2+ in Magnaporthe grisea ( Schumacher et al, 2008 ; Soriani et al, 2008 ; Zhang et al, 2009 ). Although CRZ1 and its homologs have been reported in stress response, biosynthesis of secondary metabolites and fungal virulence, there are few studies on the CRZ1 gene in basidiomycetes.…”