The Role of Membranes and Lipid-Protein Interactions in the Mg-Branch of Tetrapyrrole Biosynthesis

Abstract

Chlorophyll (Chl) is essential for photosynthesis and needs to be produced throughout the whole plant life, especially under changing light intensity and stress conditions which may result in the destruction and elimination of these pigments. All steps of the Mg-branch of tetrapyrrole biosynthesis leading to Chl formation are carried out by enzymes associated with plastid membranes. Still the significance of these protein-membrane and protein-lipid interactions in Chl synthesis and chloroplast differentiation are not very well-understood. In this review, we provide an overview on Chl biosynthesis in angiosperms with emphasis on its association with membranes and lipids. Moreover, the last steps of the pathway including the reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide), the biosynthesis of the isoprenoid phytyl moiety and the esterification of Chlide are also summarized. The unique biochemical and photophysical properties of the light-dependent NADPH:protochlorophyllide oxidoreductase (LPOR) enzyme catalyzing Pchlide photoreduction and located to peculiar tubuloreticular prolamellar body (PLB) membranes of light-deprived tissues of angiosperms and to envelope membranes, as well as to thylakoids (especially grana margins) are also reviewed. Data about the factors influencing tubuloreticular membrane formation within cells, the spectroscopic properties and the in vitro reconstitution of the native LPOR enzyme complexes are also critically discussed.

Molecular mechanisms of heavy metal adaptation of an extremophilic red algaCyanidioschyzon merolae

“…12H). The PLBs constitute the lipid reservoirs for developing thylakoids (Bykowski et al, 2020) and have been shown to prevent lipid peroxidation and RNA damage under oxidative stress conditions (Almsherqi et al, 2009; Solymosi and Mysliwa-Kurdziel, 2021). The PLBs have been observed in association with both cyanobacterial thylakoids and eukaryotic chloroplasts.…”

Dynamics of Etiolation Monitored by Seedling Morphology, Carotenoid Composition, Antioxidant Level, and Photoactivity of Protochlorophyllide in Arabidopsis thaliana

“…Physiological state of the accumulated Pchlide can be revealed by the analysis of fluorescence emission spectra measured at 77 K ( Belyaeva and Litvin, 2007 ; Solymosi and Mysliwa-Kurdziel, 2021 ). Two fluorescence bands can be easily distinguished with emission maxima at about 633 and 654 nm, similar for WT and lut2 mutant ( Figures 3G,H ).…”

“…In etiolated seedlings, at the cellular level, proplastids develop into etioplasts instead of chloroplasts (typical for light-grown plants). A paracrystalline lipid structure, called prolamellar body (PLB), is characteristic for etioplasts ( Solymosi and Aronsson, 2013 ; Armarego-Marriott et al, 2020 ; Solymosi and Mysliwa-Kurdziel, 2021 ). The biosynthesis of some protein subunits of photosynthetic complexes is inhibited, and the biosynthesis of chlorophyll (Chl) pauses at the stage of protochlorophyllide (Pchlide) formation, and they both require light to continue ( Tanaka et al, 2011 ; Pipitone et al, 2021 ).…”

“…The biosynthesis of some protein subunits of photosynthetic complexes is inhibited, and the biosynthesis of chlorophyll (Chl) pauses at the stage of protochlorophyllide (Pchlide) formation, and they both require light to continue ( Tanaka et al, 2011 ; Pipitone et al, 2021 ). In angiosperms, the conversion of Pchlide to chlorophyllide (Chlide), which is the penultimate reaction of the Chl biosynthesis pathway, is catalyzed only by the light-dependent protochlorophyllide: NADPH oxidoreductase (LPOR; EC 1.3.1.33) that requires light for its activity ( Gabruk and Mysliwa-Kurdziel, 2015 ; Heyes et al, 2021 ; Solymosi and Mysliwa-Kurdziel, 2021 ). LPOR is the major protein found in isolated PLBs ( Lindsten et al, 1988 ; von Zychlinski et al, 2005 ; Blomqvist et al, 2008 ), and vast majority of LPOR is localized in PLBs ( Ryberg and Sundqvist, 1982 ; Ikeuchi and Murakami, 1983 ).…”

“…Pchlide and LPOR accumulate in etioplasts as ternary Pchlide: LPOR: NADPH complexes along with unbound Pchlide. Those Pchlide forms can be distinguished with absorption and fluorescence spectroscopy at 77 K that have been thoroughly summarized in many reviews (e.g., Schoefs and Franck, 2003 ; Belyaeva and Litvin, 2007 , 2014 ; Solymosi and Mysliwa-Kurdziel, 2021 ). In particular, fluorescence bands of Pchlide: LPOR: NADPH complexes and that of unbound Pchlide have maxima at about 654 and 633 nm, respectively.…”