Abstract
TSK-associating protein1 (TSA1), which was identified as a protein that can interact with TONSOKU (TSK)/MGOUN3/BRUSHY1 involved in meristem maintenance, contains N-terminal putative signal peptide, novel glutamic acid-phenylalanine-glutamic acid (EFE) repeats, putative transmembrane domain, and C-terminal TSK-interacting domain. EFE repeats of recombinant TSA1 protein possesses CA2+-binding activity and the fluorescence of TSA1-GFP fusion protein appears as many spots in cytoplasm, suggesting that TSA1 is associated to endoplasmic reticulum (ER) or ER-derived vesicular organelle.
We identified disruptants for TSA1 and TSA1-like, with high sequence similarity to TSA1. However these disruptants or double disruptant did not show any tsk mutant-like morphological defects. The TSA1 and TSA1-like mRNAs were found predominantly in aerial part and roots, respectively. Furthermore expression of both of TSA1 and TSA1-like genes was induced in response to wounding and methyl jasmonate treatment. These results imply that TSA1 and TSA1-like are likely to be associated with wound-inducible organelle ER body.
