GFPperhe

GFPperhe is a term used to describe the family of green fluorescent protein (GFP) and related fluorescent proteins, including engineered variants, that share a common beta-barrel structure and a chromophore formed from a tripeptide inside the protein. The name reflects the origin of GFP from the jellyfish Aequorea victoria and the broad set of GFP-like proteins found in various organisms.

Members of the GFPperhe range from the original wild-type GFP to GFP-like proteins discovered in corals and other species, as well as numerous laboratory-engineered derivatives such as enhanced GFP and its color-shifted variants. These proteins fluoresce when excited at specific wavelengths, with spectral properties that can be tuned by mutations. The chromophore forms autocatalytically in the presence of oxygen, enabling fluorescence without external cofactors.

The GFPperhe is widely used as fluorescent reporters and tags in living cells and organisms. It enables visualization of gene expression, protein localization, movement, and interactions. The diversity of variants provides different excitation and emission maxima, brightness, maturation times, and pH stability, facilitating multicolor imaging and techniques such as Förster resonance energy transfer (FRET).

Applications often involve cloning GFPperhe genes under specific promoters, targeting sequences, or fusion to other proteins. Researchers consider factors such as codon optimization, expression level, and potential perturbation to cellular processes. Limitations include photobleaching, maturation time, sensitivity to environmental conditions, and potential cytotoxicity at high levels.

Overall, the GFPperhe represents a foundational tool in molecular and cellular biology, continually expanding through discovery of natural homologs and engineered improvements to match experimental needs. See also GFP, fluorescent proteins, and FRET.