- Takada H. [Cell surface protein Ecm33 is involved in negative feedback regulation of MAP kinase signalling and development of the in vivo real-time monitoring of MAP kinase signalling]. Yakugaku Zasshi. 2011;131:1195-200 pubmed..In addition, the Ecm33 overproducing cells displayed phenotypes closely similar to those of the pmk1 knockout cell. Collectively, Ecm33 plays a role in the negative feedback regulation of Pmk1 cell integrity signaling. ..