PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of bmcpsBioMed Centralsearchsubmit a manuscriptregisterthis articleBMC Plant Biology
 
BMC Plant Biol. 2012; 12: 31.
Published online Mar 1, 2012. doi:  10.1186/1471-2229-12-31
PMCID: PMC3311568
Coffee cysteine proteinases and related inhibitors with high expression during grain maturation and germination
Maud Lepelley,#1 Mohamed Ben Amor,#1,2 Nelly Martineau,1 Gerald Cheminade,1 Victoria Caillet,1 and James McCarthycorresponding author1
1Nestle Research and Development Center, 101 Avenue Gustave Eiffel, Tours 37097, France
2ROYAL SAT, Hacienda la Jarilla Apdo 47, 41300 San José de la Rinconada, Sevilla, Spain
corresponding authorCorresponding author.
#Contributed equally.
Maud Lepelley: maud.lepelley/at/rdto.nestle.com; Mohamed Ben Amor: BMohamed/at/satroyal.com; Nelly Martineau: martineau.nelly/at/laposte.net; Gerald Cheminade: cheminade_gerald/at/yahoo.fr; Victoria Caillet: victoria.berry/at/rdto.nestle.com; James McCarthy: james.mccarthy/at/rdto.nestle.com
Received November 13, 2011; Accepted March 1, 2012.
Abstract
Background
Cysteine proteinases perform multiple functions in seeds, including participation in remodelling polypeptides and recycling amino acids during maturation and germination. Currently, few details exist concerning these genes and proteins in coffee. Furthermore, there is limited information on the cysteine proteinase inhibitors which influence the activities of these proteinases.
Results
Two cysteine proteinase (CP) and four cysteine proteinase inhibitor (CPI) gene sequences have been identified in coffee with significant expression during the maturation and germination of coffee grain. Detailed expression analysis of the cysteine proteinase genes CcCP1 and CcCP4 in Robusta using quantitative RT-PCR showed that these transcripts accumulate primarily during grain maturation and germination/post germination. The corresponding proteins were expressed in E. coli and purified, but only one, CcCP4, which has a KDDL/KDEL C-terminal sequence, was found to be active after a short acid treatment. QRT-PCR expression analysis of the four cysteine proteinase inhibitor genes in Robusta showed that CcCPI-1 is primarily expressed in developing and germinating grain and CcCPI-4 is very highly expressed during the late post germination period, as well as in mature, but not immature leaves. Transcripts corresponding to CcCPI-2 and CcCPI-3 were detected in most tissues examined at relatively similar, but generally low levels.
Conclusions
Several cysteine proteinase and cysteine proteinase inhibitor genes with strong, relatively specific expression during coffee grain maturation and germination are presented. The temporal expression of the CcCP1 gene suggests it is involved in modifying proteins during late grain maturation and germination. The expression pattern of CcCP4, and its close identity with KDEL containing CP proteins, implies this proteinase may play a role in protein and/or cell remodelling during late grain germination, and that it is likely to play a strong role in the programmed cell death associated with post-germination of the coffee grain. Expression analysis of the cysteine proteinase inhibitor genes suggests that CcCPI-1 could primarily be involved in modulating the activity of grain CP activity; while CcCPI-4 may play roles modulating grain CP activity and in the protection of the young coffee seedlings from insects and pathogens. CcCPI-2 and CcCPI-3, having lower and more widespread expression, could be more general "house-keeping" CPI genes.
Keywords: Cysteine proteinase, Cysteine proteinase inhibitor, Proteinase activity, Coffee
Articles from BMC Plant Biology are provided here courtesy of
BioMed Central