TY - JOUR
T1 - Cell-to-cell movement of the CAPRICE protein in Arabidopsis root epidermal cell differentiation
AU - Kurata, Tetsuya
AU - Ishida, Tetsuya
AU - Kawabata-Awai, Chie
AU - Noguchi, Masahiro
AU - Hattori, Sayoko
AU - Sano, Ryosuke
AU - Nagasaka, Ryoko
AU - Tominaga, Rumi
AU - Koshino-Kimura, Yoshihiro
AU - Kato, Tomohiko
AU - Sato, Shusei
AU - Tabata, Satoshi
AU - Okada, Kiyotaka
AU - Wada, Takuji
PY - 2005/12
Y1 - 2005/12
N2 - CAPRICE (CPC), a small, R3-type Myb-like protein, is a positive regulator of root hair development in Arabidopsis. Cell-to-cell movement of CPC is important for the differentiation of epidermal cells into trichoblasts (root hair cells). CPC is transported from atrichoblasts (hairless cells), where it is expressed, to trichoblasts, and generally accumulates in their nuclei. Using truncated versions of CPC fused to GFP, we identified a signal domain that is necessary and sufficient for CPC cell-to-cell movement. This domain includes the N-terminal region and a part of the Myb domain. Amino acid substitution experiments indicated that W76 and M78 in the Myb domain are critical for targeted transport, and that W76 is crucial for the nuclear accumulation of CPC:GFP. To evaluate the tissue-specificity of CPC movement, CPC:GFP was expressed in the stele using the SHR promoter and in trichoblasts using the EGL3 promoter. CPC:GFP was able to move from trichoblasts to atrichoblasts but could not exit from the stele, suggesting the involvement of tissue-specific regulatory factors in the intercellular movement of CPC. Analyses with a secretion inhibitor, Brefeldin A, and with an rhd3 mutant defective in the secretion process in root epidermis suggested that intercellular CPC movement is mediated through plasmodesmata. Furthermore, the fusion of CPC to tandem-GFPs defined the capability of CPC to increase the size exclusion limit of plasmodesmata.
AB - CAPRICE (CPC), a small, R3-type Myb-like protein, is a positive regulator of root hair development in Arabidopsis. Cell-to-cell movement of CPC is important for the differentiation of epidermal cells into trichoblasts (root hair cells). CPC is transported from atrichoblasts (hairless cells), where it is expressed, to trichoblasts, and generally accumulates in their nuclei. Using truncated versions of CPC fused to GFP, we identified a signal domain that is necessary and sufficient for CPC cell-to-cell movement. This domain includes the N-terminal region and a part of the Myb domain. Amino acid substitution experiments indicated that W76 and M78 in the Myb domain are critical for targeted transport, and that W76 is crucial for the nuclear accumulation of CPC:GFP. To evaluate the tissue-specificity of CPC movement, CPC:GFP was expressed in the stele using the SHR promoter and in trichoblasts using the EGL3 promoter. CPC:GFP was able to move from trichoblasts to atrichoblasts but could not exit from the stele, suggesting the involvement of tissue-specific regulatory factors in the intercellular movement of CPC. Analyses with a secretion inhibitor, Brefeldin A, and with an rhd3 mutant defective in the secretion process in root epidermis suggested that intercellular CPC movement is mediated through plasmodesmata. Furthermore, the fusion of CPC to tandem-GFPs defined the capability of CPC to increase the size exclusion limit of plasmodesmata.
KW - Arabidopsis
KW - CAPRICE
KW - Epidermis
KW - Myb
KW - Protein movement
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U2 - 10.1242/dev.02139
DO - 10.1242/dev.02139
M3 - Article
C2 - 16291794
AN - SCOPUS:31144445060
VL - 132
SP - 5387
EP - 5398
JO - Journal of Embryology and Experimental Morphology
JF - Journal of Embryology and Experimental Morphology
SN - 0950-1991
IS - 24
ER -