Known potential CDPK substratesa | ||||||||||||||||||||||||||||||||||
Substrate | Substrate Sourceb | Sitec | CDPKf | Speciesg | Effecth | Refk | ||||||||||||||||||||||||||||
Metabolism | ||||||||||||||||||||||||||||||||||
nitrate reductase | leaves | TLKRTASTPFM | PKI, PKII | spinach | inactivating | 1,2 | ||||||||||||||||||||||||||||
nitrate reductase | leaves--spinach | TLKRTASTPFM | AtCPK3 | Arabidopsis | inactivating | 2,3 | ||||||||||||||||||||||||||||
PEP carboxylase | root nodules | ? | soybean | ?I | 4 | |||||||||||||||||||||||||||||
PEP carboxylase | leaves | PGEKFFSTDAQ | maize | ?i | 5 | |||||||||||||||||||||||||||||
PSII reaction center protein D1 | peptide | ? | Spirodela | activating?j | 6 | |||||||||||||||||||||||||||||
sucrose-phosphate synthase | leaves | RMRRISSVEMM | PKI | spinach | inactivating | 1,7 | ||||||||||||||||||||||||||||
sucrose synthase | recombinant--mung bean | RLTRVHSLRER | nodule CDPK | soybean | higher sucrose affinity | 8 | ||||||||||||||||||||||||||||
sucrose synthase 2 | leaves | VLSRLHSVRER | maize | localization, activating | 9,10 | |||||||||||||||||||||||||||||
sucrose synthase (nodulin-100) | root nodules | RLTRVHSLRER | soybean | localization | 11 | |||||||||||||||||||||||||||||
Stress-related Proteins | ||||||||||||||||||||||||||||||||||
two-component pseudo-response regulator | leaves | ? | McCDPK1 | ice plant | ? | 12 | ||||||||||||||||||||||||||||
PAL | recombinant--poplar | SRVAKTRTLTTAd | AtCPK1 | Arabidopsis | ? | 13 | ||||||||||||||||||||||||||||
PAL | cell cultures, recombinant--poplar | VXKRXLTX | French bean | lower Vmax | 14 | |||||||||||||||||||||||||||||
Putative Antifungal Proteins | ||||||||||||||||||||||||||||||||||
Bowman-Birk protease inhibitor | Sigma Chemical Co.--soybean | RLNSCHSACK | embryo CDPK | wheat | ? | 15 | ||||||||||||||||||||||||||||
g-thionins | seeds--yellow mustard | KLCQRPSGTWSe | embryo CDPK | wheat | ? | 16 | ||||||||||||||||||||||||||||
lipid transfer proteins | seeds--wheat, barley | XXXPCXS/TYXXG | embryo CDPK | wheat | ? | 17 | ||||||||||||||||||||||||||||
napins | seeds--kohlrabi | QLQQVISRIYQe | embryo CDPK | wheat | ? | 18 | ||||||||||||||||||||||||||||
potato carboxypeptidase inhibitor | potato tuber | CWNSARTC | embryo CDPK | wheat | ? | 19 | ||||||||||||||||||||||||||||
Ion/Water Transport | ||||||||||||||||||||||||||||||||||
aquaglyceroporin nodulin 26 | root nodules | EITKSASFLKG | soybean | higher voltage sensitivity | 20,21 | |||||||||||||||||||||||||||||
aquaglyceroporin LIMP2 | peptide | FITKNVSFLKG | Lotus | ? | 22 | |||||||||||||||||||||||||||||
aquaporin PM28A | peptide | AIKALGSFRSN | PKI, PKII | spinach | ? | 23 | ||||||||||||||||||||||||||||
Ca2+-ATPase ACA2 | recombinant | RFTANLSKRYE | AtCPK1 | Arabidopsis | inhibiting | 24 | ||||||||||||||||||||||||||||
PM H+-ATPase | roots | ? | oat, maize | ? | 25,26 | |||||||||||||||||||||||||||||
potassium channel KAT1 | guard cells | ? | Vicia faba | inhibiting | 27,28 | |||||||||||||||||||||||||||||
Other | ||||||||||||||||||||||||||||||||||
actin-depolymerizing factor | cell cultures--maize | MANARSGVAV | French bean | inhibiting?j | 29 | |||||||||||||||||||||||||||||
CDPK-related kinase | peptide | AALRALSKTLT | DcCPK1 | carrot | ? | 30 | ||||||||||||||||||||||||||||
myosin light chain | Chara | ? | Chara | ? | 31 | |||||||||||||||||||||||||||||
PI 4-kinase activator | cell cultures | ? | carrot | activation of PI 4-kinase | 32 | |||||||||||||||||||||||||||||
proteasome regulatory subunit homologue | peptide | ? | NtCDPK1 | N. tabacum | ? | 33 | ||||||||||||||||||||||||||||
self-incompatibility RNases | style | ? | pollen tube Nak-1 | N. alata | ? | 34 | ||||||||||||||||||||||||||||
serine acetyltransferase | cell cultures | ? | soybean | reduces feedback inhibition | 35 | |||||||||||||||||||||||||||||
aPotential substrates included are those convincingly shown to be phosphorylated, in vivo or in vitro, in a calcium-stimulated manner by a CDPK (rather than CaMK). In vivo data is not available in many cases. For some substrates, results for only particular species are reported due to space constraints. bThe source of the substrate used in the studies, including the organism if different from that of the CDPK. cThe amino acid phosphorylated by the CDPK is underlined, if known, and the surrounding amino acids are shown. dPAL is phosphorylated on one of the threonines in this sequence. eCDPKs phosphorylate many proteins in this class. A site for only one protein is shown. fName of the CDPK or tissue source, if different from that of the substrate. gThe plant species expressing the CDPK. hEffect of the phosphorylation by CDPK, if known. iCDPKs phosphorylate PEPC on a site important for catalytic activation, but CDPKs do not appear to activate these proteins, suggesting other factors are involved or CDPKs are not the key enzymes in vivo (Ogawa et al., 1998). jPhosphorylation of the designated site is known to be important for the given effect in vivo, but the effect of CDPK phosphorylation has not been demonstrated. k1, McMichael et al., 1995a; 2, Douglas et al., 1997; 3, Douglas et al., 1998; 4, Zhang and Chollet, 1997; 5, Ogawa et al., 1998; 6, Swegle et al., 2001.; 7, McMichael et al., 1995b; 8, Nakai et al., 1998; 9, Huber et al., 1996; 10, Winter et al., 1997; 11, Zhang et al., 1999; 12, Patharkar and Cushman, 2000; 13, Cheng et al., 2001; 14, Allwood et al., 1999; 15, Neumann et al., 1994; 16, Neumann et al., 1996a; 17, Neumann et al., 1993; 18, Neumann et al., 1996b; 19, Neumann et al., 1996c; 20, Weaver and Roberts, 1992; 21, Lee et al., 1995; 22, Guenther and Roberts, 2000; 23, Huang et al., 2001; 24, Hwang et al., 2000; 25, Harmon et al., 1996; 26, Camoni et al., 1998a; 27, Li et al., 1998; 28, Berkowitz et al., 2000; 29, Allwood et al., 2001; 30, Farmer and Choi, 1999; 31, McCurdy and Harmon, 1992. |