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Research Database PMU-SQQUID

Ca(2+)-dependent association of S100A6 (Calcyclin) with the plasma membrane and the nuclear envelope.
Stradal, TB; Gimona, M;
J Biol Chem. 1999; 274(44): 31593-31596.
Originalarbeiten (Zeitschrift)

PMU-Authors

Gimona Mario

Abstract

Expression of S100A6 (Calcyclin), a member of the S100 family and of Zn2+-binding proteins is elevated in a number of malignant tumors. In vitro the protein associates with several actin-binding proteins and annexins in a Ca2+-dependent manner. We have now studied the subcellular localization of S100A6 using a new, specific monoclonal antibody. Immunofluorescence microscopy of unfixed, ultrathin, frozen sections demonstrated a dual localization of S100A6 at the nuclear envelope and the plasma membrane of porcine smooth muscle only in the presence of Ca2+. The same localization was found by immunofluorescence and immunogold electron microscopy as well as by confocal laser scanning microscopy with cultured, fixed, human CaKi-2 and porcine ST interphase cells. Upon cell division, however, S100A6 was found exclusively in the cytoplasm. Cell fractionation studies showed that S100A6 was present in the microsomal fraction in the presence of Ca2+ and was released from this fraction by the addition of EGTA/EDTA but not by Triton X-100. The data demonstrate that S100A6 is localized both at the plasma membrane and the nuclear envelope in vivo and suggest a Ca2+-dependent interaction with annexins or other components of the nuclear envelope.


Useful keywords (using NLM MeSH Indexing)

Animals

Antibodies, Monoclonal

Antibody Specificity

Calcium/pharmacology*

Cell Compartmentation

Cell Cycle Proteins*

Cell Division

Cell Fractionation

Cell Membrane/chemistry*

Fluorescent Antibody Technique

Humans

Male

Microscopy, Immunoelectron

Muscle, Smooth

Nuclear Envelope/chemistry*

Protein Binding/drug effects

S100 Proteins/immunology

S100 Proteins/isolation*

purification*

Stomach

Swine

Testis