RING-finger photocarotenogenic repressor involved in asexual sporulation in Mucor circinelloides

• Published in: FEMS microbiology letters Vol. 280; no. 1; pp. 81 - 88
• Main Authors: Nicolás, Francisco E, Calo, Silvia, Murcia-Flores, Laura, Garre, Victoriano, Ruiz-Vázquez, Rosa M, Torres-Martínez, Santiago
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.03.2008; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Amino Acid Motifs; beta Carotene - biosynthesis; Biological and medical sciences; Biosynthesis; Carotene; Carotenoids; Deactivation; filamentous fungi; Fundamental and applied biological sciences. Psychology; Fungal Proteins - genetics; Fungal Proteins - metabolism; Gene Expression Regulation, Fungal; Gene silencing; Growth, nutrition, metabolism, transports, enzymes. Molecular biology; Inactivation; Light; light responses; Light sources; Microbiology; Mucor; Mucor - physiology; Mucor circinelloides; Mycology; Phototropism; Predictive control; Proteins; Repressor Proteins - genetics; Repressor Proteins - metabolism; RNA, Small Interfering - genetics; RNA-mediated interference; siRNA; Sporangiophores; Spores; Spores, Fungal - growth & development; Sporulation; light responses; filamentous fungi; sporulation; Fungi; Plasmid; Zygomycota; RNA; Sporulation; Mucor circinelloides; Carotenoid
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2007.01044.x

Mucor circinelloides responds to blue light by activating the biosynthesis of carotenoids and bending its sporangiophores towards the light source. The CrgA protein product acts as a repressor of carotene biosynthesis, as its inactivation leads to the overaccumulation of carotenoids in both the dark and the light. We show here that asexual sporulation in Mucor is also stimulated by light and that the crgA gene is involved in sporulation, given that lack of crgA function affects both carotenogenesis and the normal production of spores. A small interference RNA (siRNA) gene silencing approach was used to block the biosynthesis of carotenoids and to demonstrate that abnormal sporulation in crgA mutants is not a consequence of a defective production of carotenes. These results reveal an active role for the predicted CrgA product, a RING-finger protein, in the control of cellular light-regulated processes in Mucor.