Heterogeneity of (TH)phorbol 12,13-dibutyrate binding in primary mouse keratinocytes at different stages of maturation

Journal Article · Fri Nov 01 00:00:00 EST 1985 · Cancer Res.; (United States)

OSTI ID:6297673

Dunn, J A; Jeng, A Y; Yuspa, S H; Blumberg, P M

Mouse keratinocytes respond heterogeneously to phorbol esters with distinct subpopulations stimulated to proliferate or induced to differentiate. The maturation state of the epidermal cell at the time of exposure may determine its response. The binding of phorbol esters to primary mouse keratinocytes was studied under culture conditions selecting for proliferating cells or differentiating cells. (20-TH)-12-Deoxyphorbol 13-isobutyrate ((TH)-DPB) bound to both types of cells at one class of binding sites. The dissociation constant (Kd) for (TH)DPB in the proliferative cells was 69 nM and the binding at saturation (Bmax) was 1.3 pmol/mg of protein. The corresponding values in the differentiative cells were 96 nM and 1.5 pmol/mg of protein, respectively. In contrast to the results obtained with (TH)DPB, (20-TH)phorbol 12,13-dibutyrate ((TH)PDBU) bound to both cell types in a heterogeneous fashion. The site for (TH)DPB binding seemed to correspond to the higher affinity (TH)PDBU binding site. The major difference in the cells grown in the medium containing 1.2 mM CaCl2 was an increase in the Bmax of the lower affinity binding site with the other three parameters remaining similar. The state of epidermal differentiation thus appears to modulate the amount of the lower affinity binding sites for phorbol esters.

• Research Organization: National Cancer Institute, Bethesda, MD
• OSTI ID: 6297673
• Journal Information: Cancer Res.; (United States), Journal Name: Cancer Res.; (United States)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
CONFIGURATION INTERACTION
PHORBOL ESTERS
CALCIUM
CELL DIFFERENTIATION
KERATIN
KINETICS
MICE
SKIN
TRITIUM COMPOUNDS
ALKALINE EARTH METALS
ANIMALS
BODY
CARCINOGENS
ELEMENTS
ESTERS
LABELLED COMPOUNDS
MAMMALS
METALS
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RODENTS
SCLEROPROTEINS
VERTEBRATES
550301* - Cytology- Tracer Techniques