Immunogold localization of calmodulin in root caps of the maize Cultivar Merit

1990 ◽  
Vol 48 (3) ◽  
pp. 674-675
Author(s):  
P.T. Nguyen ◽  
C. Uphoff ◽  
C.L. Stinemetz
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Primary Role ◽  
Immunogold Localization ◽  
Root Tips ◽  
Electrical Currents ◽  
Considerable Evidence ◽  
Maize Cultivar ◽  
Gravity Response ◽  
Induced Changes

Considerable evidence suggest that the calcium-binding protein calmodulin (CaM) may mediate calcium action and/or transport important in the gravity response of plants. Calmodulin is present in both shoots and roots and is capable of regulating calcium transport in plant vesicles. In roots calmodulin is concentrated in the tip, the gravisensing region of the root; and is reported to be closely associated with amyloplasts, organelles suggested to play a primary role in gravi-perception. Inhibitors of CaM such as chlorpromazine, calmidazolium, and compound 48/80 interfere with the gravitropic response of both snoots and roots. The magnitude of the inhibition corresponded well with the extent to which the drug binds to endogenous CaM. Compound 48/80 and calmidazolium block gravi-induced changes in electrical currents across root tips, a phenomenon thought to be associated with the sensing of the gravity stimulus.In this study, we have investigated the subcellular distribution of CaM in graviresponsive and non-graviresponsive root caps of the maize cultivar Merit.

scholarly journals Calcium-binding protein of the chick chorioallantoic membrane. I. Immunohistochemical localization

1978 ◽  
Vol 77 (3) ◽  
pp. 743-751 ◽  
Author(s):  
RS Tuan ◽  
WA Scott ◽  
ZA Cohn
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
External Surface ◽  
Binding Protein ◽  
Chorioallantoic Membrane ◽  
Immunohistochemical Localization ◽  
Calcium Binding Protein ◽  
Transport Function ◽  
Chick Chorioallantoic Membrane

The preparation of a specific antiserum (anti-CaBP) against the calcium-binding protein (CaBP) of the chorioallantoic membrane (CAM) is described. The anti-CaBP appeared to be specific for the CaBP by immunodiffusion and immunoelectrophoresis. Application of the anti-CaBP in immunofluorescence histochemistry revealed that the CaBP is present in the CAM only at developmental ages corresponding with the expression of the calcium transport function of the membrane. Furthermore, the CaBP is localized to the ectoderm of the CAM, appears to be exposed to the entire external surface of the ectoderm, and can be shown to be associated with cells enzymatically dissociated from the CAM. These results are consistent with a functional role of the CaBP in the CAM calcium transport process.

148 DIFFERENTIAL REGULATION OF CALCIUM TRANSPORT GENES, I.E., Na+/Ca2+ EXCHANGERS, TRANSIENT RECEPTOR POTENTIAL CATION CHANNEL 6 AND CALBINDINS, IN THE DIVERSE PLACENTAL TISSUES OF CALBINDIN-D9k AND -28k KNOCKOUT MICE VIA PUTATIVE STEROIDS

2012 ◽  
Vol 24 (1) ◽  
pp. 186
Author(s):  
T. H. Koo ◽  
E. B. Jeung
Keyword(s):  
Calcium Binding ◽  
Calcium Transport ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Differential Regulation ◽  
Wild Type ◽  
Rt Pcr ◽  
Calbindin D9k ◽  
Ef Hand ◽  
Transient Receptor

During pregnancy, the placenta represents the establishment of an intimate connection between mother and fetus that is specific to mammals. Calbindins [Calbindin-D9k (CaBP-9k) and -D28k (CaBP-28k)] are proteins possessing EF-hand motifs that have a high affinity for Ca2+ ions and play an important role in the regulation and buffering of Ca2+ in the various tissues. Many types of calcium channels, intracellular calcium binding proteins, Na+/Ca2+ exchangers (NCX) and transient receptor potential cation channels (TRPV) have been found in the placenta. In this study, the calcium channel in maternal-fetal Ca2+ transport was investigated using the phenotypes of wild-type, CaBP-9k, CaBP-28k and CaBP-9k/28k knockout (KO) mouse models. Expressions of calcium transport genes in 3 dissected sections of placenta (MP: maternal, CP: central, FP: fetal) were examined by real-time RT-PCR (RT-qPCR) and Western blot analysis at gestational Day 19 in these mice. The level of TRPV6 mRNA and protein was highest in the MP and CP of CaBP-28k KO mice and the FP of CaBP-9k KO mice compared with other sections of KO mice. The level of CaBP-9k was significantly induced in CaBP-28k KO mice in MP, CP and FP compared with in WT mice, which levels were elevated from maternal to fetal sections. The expression of CaBP-28k mRNA and protein was reduced in CaBP-9k KO mice compared with WT in the 3 sections of placenta. The expression of NCX1 mRNA and protein was higher in all KO mice than in WT in MP and NCX1 was highest in CaBP-28k KO mice in CP, but strong in CaBP-9k KO mice in FP compared with other strains. These results indicate that TRPV6 and NCX1 participate in transferring calcium ions between maternal and fetal compartments and alteration of CaBP-9k/28k is involved in the intracellular Ca2+ buffering system among WT and KO mice. These results taken together indicate that TRPV6 and CaBP-9k genes may play a role as a key element in controlling placental calcium transport during pregnancy.

Low Affinity Calcium Binding Sites of the Calcium Transport ATPase of Sarcoplasmic Reticulum Membranes

1980 ◽  
Vol 35 (11-12) ◽  
pp. 1012-1018 ◽  
Author(s):  
Wilhelm Hasselbach ◽  
Vera Koenig
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Binding Sites ◽  
Calcium Binding ◽  
Calcium Transport ◽  
External Surface ◽  
Transport Atpase ◽  
Affinity Constants ◽  
Calcium Binding Sites ◽  
Short Time

Calcium binding sites having low affinity constants of < 103 ᴍ-1 were titrated in native sarcoplasmic reticulum vesicles as well as in lipid deprived membranes and in the isolated calcium transport ATPase. Short time calcium binding measurements and the determination of the calcium binding heat allow to distinguish low affinity calcium binding sites located on the external surface of the sarcoplasmic reticulum membranes from those present in the section of the transport molecule directed to the vesicular space. The same number of internal binding sites was found for preparations deprived of their lipid content as well as of preparations depleted of their lipids and of their accessorial proteins. Magnesium interferes with calcium binding to the external as well as to the internal low affinity calcium binding sites. The implications of the existence of the low affinity calcium binding sites in the internal section of the calcium transport ATPase are discussed.

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