High-affinity tuning of single fluorescent protein-type indicators by flexible linker length optimization in topology mutant.

ABSTRACT: Genetically encoded Ca²⁺ indicators (GECIs) are versatile for live imaging of cellular activities. Besides the brightness and dynamic range of signal change of GECIs, Ca²⁺ affinity is another critical parameter for successful Ca²⁺ imaging, as the concentration range of Ca²⁺ dynamics differs from low nanomolar to sub-millimolar depending on the celltype and organism. However, ultrahigh-affinity GECIs, particularly the single fluorescent protein (1FP)-type, are lacking. Here, we report a simple strategy that increases Ca²⁺ affinity through the linker length optimization in topology mutants of existing 1FP-type GECIs. The resulting ultrahigh-affinity GECIs, CaMPARI-nano, BGECO-nano, and RCaMP-nano (K_d = 17-25 nM), enable unique

SUBMITTER: Hara Y 

PROVIDER: S-EPMC11162441 | biostudies-literature | 2024 Jun

REPOSITORIES: biostudies-literature