ISCA1 and CRY4: An improbable proposition

Abstract

This manuscript was submitted to Nature Materials on December 15th 2015.\n\nIn their recent manuscript Xie and colleagues argue that the pigeon ISCA1/CRY4 complex acts as a magnetic protein biocompass having unambiguously proved that these two proteins interact forming a complex with unique biophysical features (1). We do not think the evidence presented in the manuscript supports this conclusion. Firstly, the authors provide no data (such as a reciprocal co-immunoprecipitation from retinal tissue) that demonstrates that ISCA1 and CRY4 interact in vivo, instead the conclusions are based primarily on overexpression in E.coli and in vitro reconstitution experiments. Secondly, their experiments have not employed the correct full length version of CRY4. The CRY4 protein expressed by Xie and colleagues was only 497 amino acids in length. We extracted mRNA from the pigeon retina (Invitrogen, 610.11), generated cDNA (Clontech, 121311), and performed rap ...