Lectin-induced activation of platelets may require only limited phosphorylation of the 47K protein

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

OSTI ID:5234033

Ganguly, C; Chelladurai, M; Ganguly, P

Wheat germ agglutinin (WGA) is an N-acetylglucosamine (Glc-NAc) specific lectin which can activate platelets. Like thrombin, stimulation of platelets by WGA is accompanied by enhanced phosphorylation of two polypeptides of M/sub r/ 47K and 20K. Addition of GlcNAc at different time intervals arrested that aggregation of platelets by WGA and paralleled the modification of phosphorylation of the 47K polypeptide. So, the phosphorylation of the 47K polypeptide may regulate the WGA-receptor mediated stimulation of platelets. However, the ratio of phosphoserine to phosphothreonine in the 47K protein was markedly different in WGA-activated than thrombin-stimulated platelets. Thus, the molecular mechanism of action of thrombin and WGA could be different. To explore this idea, /sup 32/P/sub i/-labeled platelets were stimulated with WGA and the activation arrested with N-acetyl-glucosamine at different times. Two-dimensional gel electrophoresis of total protein at 5s showed only two phosphorylated species of 47K protein. At 60s, maximally four phosphorylated species were noted. In contrast, with thrombin using the same technique, seven to nine phosphorylated components have been reported. These results suggest that the different activators of platelets may act by different mechanisms. In addition, activation of platelets may require only limited levels of phosphorylation of the 47K polypeptide.

• Research Organization: Univ. of Puerto Rico, San Juan
• OSTI ID: 5234033
• Report Number(s): CONF-8606151-; TRN: 86-031409
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
AGGLUTININS
BIOCHEMICAL REACTION KINETICS
BLOOD PLATELETS
BLOOD COAGULATION
POLYPEPTIDES
PHOSPHORYLATION
ELECTROPHORESIS
GLUCOSAMINE
LECTINS
PHOSPHORUS 32
TRACER TECHNIQUES
AMINES
ANTIBODIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
HEXOSAMINES
HEXOSES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MATERIALS
MONOSACCHARIDES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PEPTIDES
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
SACCHARIDES
550201* - Biochemistry- Tracer Techniques