Extracellular calmodulin: A polypeptide signal in plants?

2001 ◽  
Vol 44 (5) ◽  
pp. 449-460 ◽  
Author(s):  
Daye Sun ◽  
Wenqiang Tang ◽  
Ligeng Ma
Keyword(s):  
Extracellular Calmodulin

Exogenous calmodulin potentiates vasodilation elicited by phospholipid-associated VIP in vivo

1999 ◽  
Vol 276 (5) ◽  
pp. R1359-R1365 ◽  
Author(s):  
Hiroyuki Ikezaki ◽  
Manisha Patel ◽  
Hayat Önyüksel ◽  
Syed R. Akhter ◽  
Xiao-Pei Gao ◽  
...  
Keyword(s):  
Active Sites ◽  
Calcium Ionophore ◽  
Cheek Pouch ◽  
Induced Responses ◽  
Hamster Cheek Pouch ◽  
Sterically Stabilized Liposomes ◽  
Extracellular Calmodulin ◽  
Peripheral Microcirculation

The purpose of this study was to determine whether exogenous calmodulin potentiates vasoactive intestinal peptide (VIP)-induced vasodilation in vivo and, if so, whether this response is amplified by association of VIP with sterically stabilized liposomes. Using intravital microscopy, we found that calmodulin suffused together with aqueous and liposomal VIP did not potentiate vasodilation elicited by VIP in the in situ hamster cheek pouch. However, preincubation of calmodulin with liposomal, but not aqueous, VIP for 1 and 2 h and overnight at 4°C before suffusion significantly potentiated vasodilation ( P < 0.05). Calmodulin-induced responses were significantly attenuated by calmidazolium, trifluoperazine, and N G-nitro-l-arginine methyl ester (l-NAME) but notd-NAME. The effects ofl-NAME were reversed byl- but notd-arginine. Indomethacin had no significant effects on calmodulin-induced responses. Calmodulin had no significant effects on adenosine-, isoproterenol-, acetylcholine-, and calcium ionophore A-23187-induced vasodilation. Collectively, these data indicate that exogenous calmodulin amplifies vasodilation elicited by phospholipid-associated, but not aqueous, VIP in the in situ peripheral microcirculation in a specific, calmodulin active sites-, and nitric oxide-dependent fashion. We suggest that extracellular calmodulin, phospholipids, and VIP form a novel functionally coordinated class of endogenous vasodilators.

Extracellular calmodulin-binding proteins in plants: purification of a 21-kDa calmodulin-binding protein

Planta ◽  
1996 ◽  
Vol 198 (4) ◽  
pp. 510-516 ◽  
Author(s):  
Tang Jun ◽  
Wu Shupin ◽  
Bai Juan ◽  
Sun Daye
Keyword(s):  
Binding Proteins ◽  
Binding Protein ◽  
Calmodulin Binding ◽  
Extracellular Calmodulin

Effects of extracellular calmodulin on pollen germination and tube growth

1998 ◽  
Vol 43 (2) ◽  
pp. 143-146 ◽  
Author(s):  
Ligeng Ma ◽  
Xiaodong Xu ◽  
Sujuan Cui ◽  
Daye Sun
Keyword(s):  
Pollen Germination ◽  
Tube Growth ◽  
Extracellular Calmodulin

scholarly journals An extracellular role for calmodulin-like activity in cell proliferation

1988 ◽  
Vol 253 (3) ◽  
pp. 877-884 ◽  
Author(s):  
G Crocker ◽  
R A Dawson ◽  
C H Barton ◽  
S MacNeil
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
K562 Cells ◽  
Conditioned Media ◽  
Thymidine Uptake ◽  
Related Protein ◽  
Calmodulin Antagonist ◽  
Agarose Beads ◽  
Extracellular Calmodulin ◽  
Cell Densities

1. Addition of extracellular pure pig brain calmodulin was found to modulate DNA synthesis and cell proliferation in K562 human leukaemic lymphocytes. At lower cell densities calmodulin significantly stimulated [3H]thymidine uptake; at higher densities it decreased it. 2. A protein biochemically indistinguishable from calmodulin was detected in the cell-conditioned media of rapidly dividing K562 cells. The concentration of calmodulin-like activity found in the conditioned media of these and a range of other normal and neoplastic cells (250-1636 ng/ml) was of the same order as would stimulate DNA synthesis in subconfluent cells. 3. Amounts of extracellular calmodulin-like activity and immunoreactivity varied during cell growth from low to high density, a peak of extracellular calmodulin preceding DNA synthesis in synchronized K562 cells. Extracellular calmodulin concentrations did not correlate with the presence of lactate dehydrogenase in the medium. 4. Inhibition of extracellular calmodulin activity by calmodulin antagonist immobilized on agarose beads, or by antibody to calmodulin, significantly decreased DNA synthesis. 5. These data strongly suggest that calmodulin or a very closely related protein can influence mitosis through an extracellular mechanism.

Extracellular calmodulin acceleratesrbcS-GUS expression in suspension-cultured transgenic tobacco cell

2000 ◽  
Vol 45 (22) ◽  
pp. 2089-2092 ◽  
Author(s):  
Ligeng Ma ◽  
Junli Zhou ◽  
Suqiao Zhang ◽  
Qiang Liu ◽  
Daye Sun
Keyword(s):  
Transgenic Tobacco ◽  
Gus Expression ◽  
Tobacco Cell ◽  
Extracellular Calmodulin
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