Modulation of P1798 lymphosarcoma proliferation by protein phosphorylation
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
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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CELL PROLIFERATION
MODULATION
LYMPHOSARCOMAS
PHOSPHOTRANSFERASES
ENZYME ACTIVITY
PHOSPHORYLATION
ADRENALINE
AMP
BIOCHEMISTRY
CELL DIVISION
DNA
DOSE-RESPONSE RELATIONSHIPS
MUSCLES
PROSTAGLANDINS
PURIFICATION
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ADRENAL HORMONES
AUTONOMIC NERVOUS SYSTEM AGENTS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CHEMICAL REACTIONS
CHEMISTRY
DISEASES
DRUGS
ENZYMES
HORMONES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYMPHOMAS
NEOPLASMS
NEUROREGULATORS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
SARCOMAS
STEROID HORMONES
SYMPATHOMIMETICS
TRANSFERASES
550201* - Biochemistry- Tracer Techniques