% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@PHDTHESIS{Chretien:626020,
      author       = {Chretien, Anais},
      othercontributors = {Pearson, Arwen and Meier, Chris},
      title        = {{E}lucidating signal transduction in multi-domain {BLUF}
                      photoreceptors by studying the {P}hotoactivated {A}denylate
                      {C}yclase {O}a{PAC}},
      school       = {University of Hamburg},
      type         = {Dissertation},
      reportid     = {PUBDB-2025-01257},
      pages        = {258},
      year         = {2024},
      note         = {Dissertation, University of Hamburg, 2024},
      abstract     = {Photosensory receptors, essential molecular entities across
                      all domains of life, enable organisms to detect and respond
                      to light stimuli, underpinning their critical involvement in
                      regulating biological processes such as phototropism,
                      circadian rhythms, photomorphogenesis, and photosynthesis.
                      Among the myriad types of photosensory receptors, blue light
                      sensing proteins such as Blue Light Using Flavin (BLUF)
                      photoreceptors distinguish themselves through their ability
                      to utilize blue light for signalling. Characterized by the
                      conserved structure of their sensor domain, BLUF
                      photoreceptors are found in a wide array of organisms, from
                      bacteria and algae to plants and certain fungi. Known for
                      their capacity to bind flavin chromophores, typically flavin
                      adenine dinucleotide (FAD), they undergo conformational
                      changes upon blue photon absorption, leading to downstream
                      signalling events, highlighting their pivotal role in the
                      adaptive responses of various organisms to light. This
                      dissertation provides a comprehensive exploration of the
                      BLUF photoreceptors, particularly focusing on the
                      Photoactivated Adenylate Cyclase protein from Oscillatoria
                      acuminata (OaPAC), which comprises a BLUF sensor domain
                      linked to an Adenylate Cyclase (AC) effector domain,
                      catalysing the conversion of ATP into cAMP. This study aims
                      to elucidate the photoactivation mechanism of OaPAC and the
                      ensuing signal transduction pathway, employing an
                      integrative approach that leverages time-resolved
                      crystallography, small angle X-ray scattering, spectroscopy,
                      and biochemical characterization techniques. Special
                      emphasis is placed on the Tyr-Gln-Met triad in the BLUF
                      domain, which plays a crucial role in the initial
                      light-induced rearrangements. Additionally, significant
                      attention is given to the less understood aspects of BLUF
                      photoreceptors, particularly the transduction of the initial
                      light signal to more distal parts of the protein, which
                      ultimately leads to biological activity. This research
                      identifies a Met(out)/Trp(in) transition as a crucial
                      element in conveying the signal to the α-helix linker
                      region. Finally, structural models of OaPAC with ATP bound
                      in the active site, along with complementary FTIR
                      investigations, provide a thorough understanding of ATP
                      binding and allosteric communication. As a result, the
                      research presented in this dissertation not only expands the
                      fundamental understanding of BLUF photoreceptor biology, but
                      also provides a framework for future studies aimed at
                      deciphering complete signal transduction pathways in
                      multi-domain BLUF photoreceptors and towards the development
                      of optogenetic tools.},
      pnm          = {PHGS, VH-GS-500 - PIER Helmholtz Graduate School
                      $(2015_IFV-VH-GS-500)$},
      pid          = {$G:(DE-HGF)2015_IFV-VH-GS-500$},
      typ          = {PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:gbv:18-ediss-121292},
      url          = {https://bib-pubdb1.desy.de/record/626020},
}