TY - JOUR
T1 - In vitro prenylation of the small GTPase Rac13 of cotton
AU - Trainin, Taiy
AU - Shmuel, Miri
AU - Delmer, Deborah P.
PY - 1996/12
Y1 - 1996/12
N2 - Previous work (D.P. Delmer, J. Pear, A. Andrawis, D. Stalker [1995] Mol Gen Genet 248: 43-51) has identified a gene in cotton (Gossypium hirsutum), Rac13, that encodes a small, signal-transducing GTPase and shows high expression in the fiber at the time of transition from primary to secondary wall synthesis. Since Rac13 may be important in signal transduction pathway(s), regulatins the onset of fiber secondary wall synthesis, we continue to characterize Rac13 by determining its ability to undergo posttranslational modification. In animals Rac proteins contain the C- terminal consensus sequence CaaL (where 'a' can be any aliphatic residue), which is a site for geranylgeranylation (B.T. Kinsella, R.A. Erdman, W.A. Maltese [1994] J Biol Chem 266: 97869794). We have identified activities in developing cotton fibers that resemble in specificity the geranylgeranyl- and farnesyltransferases of animals and yeast. In addition, using prenyltransferases from rabbit reticulocytes, we show that Rac13, having a C- terminal sequence of CAFL, can serve as an in vitro substrate for geranylgeranylation but not farnesylation. However, the presence of the uncommon penultimate F residue appears to slow the rate of prenylation considerably compared with other acceptors.
AB - Previous work (D.P. Delmer, J. Pear, A. Andrawis, D. Stalker [1995] Mol Gen Genet 248: 43-51) has identified a gene in cotton (Gossypium hirsutum), Rac13, that encodes a small, signal-transducing GTPase and shows high expression in the fiber at the time of transition from primary to secondary wall synthesis. Since Rac13 may be important in signal transduction pathway(s), regulatins the onset of fiber secondary wall synthesis, we continue to characterize Rac13 by determining its ability to undergo posttranslational modification. In animals Rac proteins contain the C- terminal consensus sequence CaaL (where 'a' can be any aliphatic residue), which is a site for geranylgeranylation (B.T. Kinsella, R.A. Erdman, W.A. Maltese [1994] J Biol Chem 266: 97869794). We have identified activities in developing cotton fibers that resemble in specificity the geranylgeranyl- and farnesyltransferases of animals and yeast. In addition, using prenyltransferases from rabbit reticulocytes, we show that Rac13, having a C- terminal sequence of CAFL, can serve as an in vitro substrate for geranylgeranylation but not farnesylation. However, the presence of the uncommon penultimate F residue appears to slow the rate of prenylation considerably compared with other acceptors.
UR - http://www.scopus.com/inward/record.url?scp=0030468525&partnerID=8YFLogxK
U2 - 10.1104/pp.112.4.1491
DO - 10.1104/pp.112.4.1491
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AN - SCOPUS:0030468525
SN - 0032-0889
VL - 112
SP - 1491
EP - 1497
JO - Plant Physiology
JF - Plant Physiology
IS - 4
ER -