Human neutrophil calmodulin-binding proteins: identification of the calmodulin-dependent protein phosphatase

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7171029

Blackburn, W D; Tallant, E A; Wallace, R W

The molecular events in linking neutrophil activation and ligand binding to specific membrane receptors are mediated in part by an increase in intracellular Ca/sup 2 +/. One mechanism by which Ca/sup 2 +/ may trigger neutrophil activation is through Ca/sup 2 +//calmodulin (CaM)-regulated proteins and enzymes. To determine which Ca/sup 2 +//CaM-regulated enzymes may be present in the neutrophil, they have used Western blotting techniques and /sup 125/I-CaM to identify neutrophil CaM-binding proteins. Eleven proteins with molecular weights ranging from 230K to 13.5K bound /sup 125/I-CaM in a Ca/sup 2 +/-dependent manner. One predominant region of /sup 125/I-Cam binding was to a 59K protein; a protein with an identical mobility was labeled by an antisera against brain CaM-dependent phosphatase. Ca/sup 2 +/-dependent phosphatase activity, which was inhibited by the CaM antagonist trifluoperazine, was detected in a neutrophil extract; a radioimmunoassay for the phosphatase indicated that it was present in the extract at approximately 0.2 ..mu..g/mg protein. Most of the CaM-binding proteins, including the 59K protein, were rapidly degraded upon lysis of the neutrophil. There was a close correlation between the degradation of the 59K protein and the loss of Ca/sup 2 +/-dependent phosphatase activity in the neutrophil extract. Thus, human neutrophils contain numerous CaM-binding proteins which are presumably Ca/sup 2 +//calmodulin-regulated enzymes and proteins; the 59K protein is a CaM-dependent phosphatase.

• Research Organization: Univ. of Alabama, Birmingham
• OSTI ID: 7171029
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CALCIUM COMPOUNDS
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
ESTERASES
HYDROLASES
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEUKOCYTES
LIGANDS
LYSIS
MAMMALS
MAN
MATERIALS
MEMBRANE PROTEINS
MEMBRANES
MOLECULAR WEIGHT
NEUTROPHILS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PHOSPHATASES
PRIMATES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNOLOGY
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
VERTEBRATES