Control of a four-color sensing photoreceptor by a two-color sensing photoreceptor reveals complex light regulation in cyanobacteria.

نویسندگان

  • Adam N Bussell
  • David M Kehoe
چکیده

Photoreceptors are biologically important for sensing changes in the color and intensity of ambient light and, for photosynthetic organisms, processing this light information to optimize food production through photosynthesis. Cyanobacteria are an evolutionarily and ecologically important prokaryotic group of oxygenic photosynthesizers that contain cyanobacteriochrome (CBCR) photoreceptors, whose family members sense nearly the entire visible spectrum of light colors. Some cyanobacteria contain 12 to 15 different CBCRs, and many family members contain multiple light-sensing domains. However, the complex interactions that must be occurring within and between these photoreceptors remain unexplored. Here we describe the regulation and photobiology of a unique CBCR called IflA (influenced by far-red light), demonstrating that a second CBCR called RcaE strongly regulates IflA abundance and that IflA uses two distinct photosensory domains to respond to four different light colors: blue, green, red, and far-red. The absorption of red or far-red light by one domain affects the conformation of the other domain, and the rate of relaxation of one of these domains is influenced by the conformation of the other. Deletion of iflA results in delayed growth at low cell density, suggesting that IflA accelerates growth under this condition, apparently by sensing the ratio of red to far-red light in the environment. The types of complex photobiological interactions described here, both between unrelated CBCR family members and within photosensory domains of a single CBCR, may be advantageous for species using these photoreceptors in aquatic environments, where light color ratios are influenced by many biotic and abiotic factors.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Light-dependent attenuation of phycoerythrin gene expression reveals convergent evolution of green light sensing in cyanobacteria.

The colorful process of chromatic acclimation allows many cyanobacteria to change their pigmentation in response to ambient light color changes. In red light, cells produce red-absorbing phycocyanin (PC), whereas in green light, green-absorbing phycoerythrin (PE) is made. Controlling these pigment levels increases fitness by optimizing photosynthetic activity in different light color environmen...

متن کامل

Two Cyanobacterial Photoreceptors Regulate Photosynthetic Light Harvesting by Sensing Teal, Green, Yellow, and Red Light.

UNLABELLED The genomes of many photosynthetic and nonphotosynthetic bacteria encode numerous phytochrome superfamily photoreceptors whose functions and interactions are largely unknown. Cyanobacterial genomes encode particularly large numbers of phytochrome superfamily members called cyanobacteriochromes. These have diverse light color-sensing abilities, and their functions and interactions are...

متن کامل

Morphology of retinal photoreceptor layer in continuous light-exposed and dark-adapted male cats

The morphology of retinal photoreceptor layer was studied in continuous light-exposed and dark-adapteddomestic male cats (Felis catus). The eyes of 12 healthy adult cats (4 in continuous light-exposed group, 4 in continuous dark-adapted group, and 4 in control group) were routinely fixed and studied by electron microscope. Results showed that the general structure of photoreceptor layer in this...

متن کامل

Effect of let-7a overexpression on the differentiation of conjunctiva mesenchymal stem cells into photoreceptor-like cells

Objective(s): MicroRNAs (miRNAs) could regulate many cellular processes such as proliferation and differentiation. let-7a miRNA is one of the key regulators in the developmental transition of retinal progenitor cells into differentiated cells. Current evidence suggests that mesenchymal stem cells (MSCs) can isolate from various tissues such as bone marrow and conjuncti...

متن کامل

Representation of Primary Color Tone Reproduction Curves their Stabilization

This paper proposes and compares different methods of representing the primary color tone reproduction curves (TRC) for the stabilization control in a color xerographic printing process. TRC stabilization is vital in maintaining high consistency in color printout. Colors are typically represented by a 3-dimensional representation such as the CIELAB or CIEXYZ colorspaces. For stabilization contr...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Proceedings of the National Academy of Sciences of the United States of America

دوره 110 31  شماره 

صفحات  -

تاریخ انتشار 2013