Modulation of P1798 lymphosarcoma proliferation by protein phosphorylation

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6000975

Michnoff, C A.H.

The role of protein kinases in modulating cell proliferation was examined. Studies characterized the regulation of cell proliferation by adenosine 3':5'-monophosphate-dependent protein kinase (cA-Pk). Calcium/calmodulin-dependent myosin light chain kinase (MLCK) was isolated and examined as a potential substrate regulated by cA-PK in the rapidly proliferating P1798 lymphosarcoma. Modulation of cell proliferation by cA-PK was characterized by quantitating cell division by (methyl-/sup 3/H) thymidine ((/sup 3/H)-dT) incorporation into DNA, cAMP accumulations, and activation of cA-PK using P1798 lymphosarcoma cells. Epinephrine and prostaglandin E/sub 1/ (PGE/sub 1/) were demonstrated to suppress (/sup 3/H)-dT incorporation into DNA, to stimulate cAMP accumulation, and to activate cA-PK with dose-dependency. Calcium/calmodulin-dependent MLCK was partially purified from P1798 lymphosarcoma. P1798 MLCK phosphorylated myosin regulatory light chains (P-LC) from thymus, cardiac and skeletal muscles. One mol (/sup 32/Pi) was transferred into one mol cardiac or skeletal P-LC by P1798 MLCK. Apparent Km values of 65 ..mu..M and 51 ..mu..M were determined for ATP and cardiac P-LC, respectively. The apparent molecular weight of P1798 MLCK was 135,000. P1798 MLCK was phosphorylated by cA-PK. Phosphorylated MLCK showed a 41% decrease in calcium-dependent activity. Two additional protein kinases from P1798 lymphosarcoma phosphorylated cardiac and skeletal light chains (MLC).

• Research Organization: North Texas State Univ., Denton (USA)
• OSTI ID: 6000975
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ADRENALINE
AMP
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMISTRY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CELL DIVISION
CELL PROLIFERATION
CHEMICAL REACTIONS
CHEMISTRY
DISEASES
DNA
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ENZYME ACTIVITY
ENZYMES
HORMONES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYMPHOMAS
LYMPHOSARCOMAS
MODULATION
MUSCLES
NEOPLASMS
NEUROREGULATORS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROSTAGLANDINS
PURIFICATION
SARCOMAS
STEROID HORMONES
SYMPATHOMIMETICS
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS