Monkey Kidney Cells with mRuby-Actin
Actin molecules hardly differ in their amino acid sequences throughout a large variety of species, which suggests the protein is of a highly conserved nature. Actin's ability to manipulate cellular shape and locomotion depends on the protein's relationship with a number of accessory proteins including actinogelin (an actin-binding protein).
The African green monkey kidney fibroblast cells (CV-1 line) featured in the digital video sequence presented in this section were fluorescently tagged with mRuby fused to actin, visualizing the cytoskeleton. Actin microfilaments are one of the primary components that comprise the cytoskeletal network and function in an array of important cellular activities, such as cytokinesis, cell motility, cell signaling, vesicle trafficking, and maintenance of structural integrity. Each actin microfilament (F-actin) is composed of head-to-tail polymerized actin monomeric subunits, known as globular actin (G-actin).
mRuby is a bright, monomeric variant of the far-red fluorescent protein eqFP611 originally isolated from the sea anemone Entacmaea quadricolor. Relative to its parent protein, mRuby features 29 mutations. Currently mRuby is one of the brightest monomeric red fluorescent proteins in existence. The excitation and emission maxima of mRuby occur at 558 nm and 605 nm, respectively.