Tespa1 is a novel inositol 1,4,5-trisphosphate receptor binding protein in T and B lymphocytes

Hiroshi Matsuzaki; Takahiro Fujimoto; Takeharu Ota; Masahiro Ogawa; Toshiyuki Tsunoda; Keiko Doi; Masato Hamabashiri; Masatoshi Tanaka; Senji Shirasawa

doi:10.1016/j.fob.2012.08.005

Tespa1 is a novel inositol 1,4,5-trisphosphate receptor binding protein in T and B lymphocytes

FEBS Open Bio. 2012 Sep 4:2:255-9. doi: 10.1016/j.fob.2012.08.005. Print 2012.

Authors

Hiroshi Matsuzaki¹, Takahiro Fujimoto, Takeharu Ota, Masahiro Ogawa, Toshiyuki Tsunoda, Keiko Doi, Masato Hamabashiri, Masatoshi Tanaka, Senji Shirasawa

Affiliation

¹ Department of Cell Biology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.

Abstract

Tespa1 has been recently reported to be a critical molecule in T-cell development, however, the precise molecular mechanisms of Tespa1 remain elusive. Here, we demonstrate that Tespa1 shows amino-acid sequence homology to KRAS-induced actin-interacting protein (KRAP), an inositol 1,4,5-trisphosphate receptor (IP3R) binding protein, and that Tespa1 physically associates with IP3R in T and B lymphocytes. Two-consecutive phenylalanine residues (Phe185/Phe186) in Tespa1, which are conserved between Tespa1 and KRAP, are indispensable for the association between Tespa1 and IP3R. These findings suggest that Tespa1 plays critical roles in the immune system through the regulation of the IP3R.

Keywords: IP3R; IP3R, Inositol 1,4,5-trisphosphate receptor; KRAP, KRAS-induced actin-interacting protein.; Lymphocyte; Protein–protein interaction; Spleen; Tespa1; Tespa1, thymocyte-expressed positive selection-associated 1; Thymus.