Figure 1. The zebrafish Trak proteins are paralogous to each other, and EGFP-tagged Trak1a and 2 proteins localize to the mitochondria when expressed in mammalian tissue culture cells.

A. D. rerio sequences used for alignment: trak1a (GenBank XM_001921277.3), si:dkey-28e7.3-201 (ENSDARG00000074508), and trak2-201: (ENSDARG00000102471). The star represents the position of an intron in the cloned trak1a gene to generate a truncated protein (Trak1 ΔC). B. Various fish species also have three distinct genes which predominantly group with trak1a, trak2, and si:dkey-28e7.3. C. COS7 cells were transfected with zebrafish Trak1a/pEGFP, Trak2/pEGFP, or Trak1 ΔC/pEGFP plasmids using Lipofectamine 3000 (GFP). After expression, cells were fixed with methanol and immunostained to identify mitochondria using a human TOMM40 primary antibody and TRITC secondary antibody. Nuclei were counterstained with DAPI. Overlay is presented at far right. Images were collected at 630X magnification on a Zeiss LSM 700 confocal microscope, and representative images are displayed.