PMID- 12618146
OWN - NLM
STAT- MEDLINE
DCOM- 20030926
LR  - 20190922
IS  - 0143-4160 (Print)
IS  - 0143-4160 (Linking)
VI  - 33
IP  - 4
DP  - 2003 Apr
TI  - Intracellular Ca(2+) regulates the cellular iron uptake in K562 cells.
PG  - 257-66
AB  - Fluorescence quenching was used to study the kinetics of the transferrin receptor 
      (TfR)-mediated iron uptake in the calcein-loaded K562 cells. It was found that 
      elevation of intracellular free Ca(2+) ([Ca(2+)](i)) by thapsigargin (TG) speeds 
      up the initial rate of iron uptake and increases the overall capacity of the 
      cells in taking up iron. Depletion of intracellular Ca(2+) or complete chelation 
      of extracellular Ca(2+) results in complete inhibition of the iron uptake in 
      cells. To gain insight into molecular mechanism, IANBD-labeled transferrin (Tf) 
      and microscopic fluorescence imaging were used to observe the endocytosis and 
      recycling of the Tf-TfR complex in single live cells. The study showed that the 
      preincubation of cells with TG or phorbol myristate acetate (PMA), the direct 
      activator of protein kinase C (PKC), accelerated the endocytosis and recycling of 
      the complex in a dose-dependent manner. W-7, the calmodulin antagonist, and 
      GF109203X, a selected cell-permeant inhibitor of PKC, can reverse the 
      acceleration. Analysis of actin polymerization in controlled, 
      [Ca(2+)](i)-elevated and W-7-treated cells revealed that the actin polymerization 
      is enhanced as [Ca(2+)](i) is raised, but reduced by W-7. The results suggest 
      that the regulation of actin polymerization by intracellular Ca(2+) may play a 
      central role in Ca(2+)-dependent iron uptake.
FAU - Ci, Weimin
AU  - Ci W
AD  - Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang 
      District, Beijing 100101, China.
FAU - Li, Wenyu
AU  - Li W
FAU - Ke, Ya
AU  - Ke Y
FAU - Qian, Zhong-Ming
AU  - Qian ZM
FAU - Shen, Xun
AU  - Shen X
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Cell Calcium
JT  - Cell calcium
JID - 8006226
RN  - 0 (Actins)
RN  - 0 (Chelating Agents)
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Fluoresceins)
RN  - 0 (Oxadiazoles)
RN  - 0 (Polymers)
RN  - 0 (Receptors, Transferrin)
RN  - 0 (Transferrin)
RN  - 67013-48-3 (4-(N-(iodoacetoxy)ethyl-N-methyl)amino-7-nitrobenz-2-oxa-1,3-diazole)
RN  - E1UOL152H7 (Iron)
RN  - EC 2.7.11.13 (Protein Kinase C)
RN  - SY7Q814VUP (Calcium)
RN  - V0YM2B16TS (fluorexon)
SB  - IM
MH  - Actins/biosynthesis/drug effects
MH  - Calcium/*metabolism
MH  - Calcium Signaling/drug effects/*physiology
MH  - Chelating Agents/pharmacology
MH  - Endocytosis/drug effects/*physiology
MH  - Enzyme Inhibitors/pharmacology
MH  - Eukaryotic Cells/drug effects/*metabolism
MH  - Fluoresceins
MH  - Humans
MH  - Intracellular Fluid/drug effects/*metabolism
MH  - Iron/*metabolism
MH  - Oxadiazoles
MH  - Polymers/metabolism
MH  - Protein Kinase C/drug effects/metabolism
MH  - Receptors, Transferrin/drug effects/*metabolism
MH  - Transferrin/metabolism
MH  - Tumor Cells, Cultured
MH  - Up-Regulation/drug effects/physiology
EDAT- 2003/03/06 04:00
MHDA- 2003/09/27 05:00
CRDT- 2003/03/06 04:00
PHST- 2003/03/06 04:00 [pubmed]
PHST- 2003/09/27 05:00 [medline]
PHST- 2003/03/06 04:00 [entrez]
AID - S0143416002002403 [pii]
AID - 10.1016/s0143-4160(02)00240-3 [doi]
PST - ppublish
SO  - Cell Calcium. 2003 Apr;33(4):257-66. doi: 10.1016/s0143-4160(02)00240-3.