Chromatophores efficiently promote light-driven ATP synthesis and DNA transcription inside hybrid multicompartment artificial cells

Abstract

The construction of energetically autonomous artificial protocells is one of the most ambitious goals in bottom-up synthetic biology. Here, we show an efficient manner to build adenosine 5′-triphosphate (ATP) synthesizing hybrid multicompartment protocells. Bacterial chromatophores from Rhodobacter sphaeroides accomplish the photophosphorylation of adenosine 5′-diphosphate (ADP) to ATP, functioning as nanosized photosynthetic organellae when encapsulated inside artificial giant phospholipid vesicles (ATP production rate up to ∼100 ATP∙s−1 per ATP synthase). The chromatophore morphology and the orientation of the photophosphorylation proteins were characterized by cryo-electron microscopy (cryo-EM) and time-resolved spectroscopy. The freshly synthesized ATP has been employed for sustaining the transcription of a DNA gene, following the RNA biosynthesis inside individual vesicles by confocal microscopy. The hybrid multicompartment approach here proposed is very promising for the construction of full-fledged artificial protocells because it relies on easy-to-obtain and ready-to-use chromatophores, paving the way for artificial simplified-autotroph protocells (ASAPs).

Synthetic cells in biomedical applications

“…A common strategy is to create a proton gradient that can then be used by ATP synthase to drive ATP production. To generate the proton gradient, light‐activated bacteriorhodopsin (Z. Chen et al, 2019; Choi & Montemagno, 2005; Dhir et al, 2018) or other proton pumping systems (Altamura et al, n.d.; Cladera et al, 1996; X. Feng et al, 2016; Steinberg‐Yfrach et al, 1998) can be embedded in the membrane. The resulting light‐dependent ATP synthesis can then drive IVTT protein production (Berhanu et al, 2019) or other ATP‐dependent processes.…”

Build-a-Cell: Engineering a Synthetic Cell Community

“…Build-a-Cell researchers can already program most cellular functions individually [8], from genome replication [9][10][11] to ATP generation [12][13][14][15][16]. As these successes pile up, the next challenge for the community is to combine functions and "boot up" a fully functioning cell [17].…”

A Wetware Embodied AI? Towards an Autopoietic Organizational Approach Grounded in Synthetic Biology

“…This is done by using biomolecules, or supposedly primitive compounds, or even artificial materials. Interesting hybrid combinations are also possible, as in the case of biological organellae inserted in artificial vesicles aiming at producing ATP ( Altamura et al, 2021 ). Bottom-up SB, actually, can be considered the modern descendant of origins of life research, and counts as more proximal relatives the entire branch of chemical/biochemical reactions inside microcompartments, and the 1990s chemical autopoiesis ( Bachmann et al, 1990 ; Walde et al, 1994 ).…”