1. Protein Phosphatase Type 1-Dependent Dephosphorylation of the Retinoblastoma Tumor Suppressor Protein in Ultraviolet-Irradiated Human Skin and Keratinocytes 
Malcolm J. Edwards 
Journal of Investigative Dermatology 
Volume 115, Issue 1, Pages (July 2000)
DOI: /j x
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
Immunohistochemical localization of pRB in human skin. Skin slices were exposed to 200 J per cm2 of UV and allowed to recover for up to 8 h at 37°C in growth medium. Unirradiated skin (a), showing anti-RB-Ab2 polyclonal antibody staining in the nuclei of basal and spinous layer cells of the epidermis and in the cellular compartment of the dermis. In UV-irradiated skin (b), there appears to be a decrease in the nuclear anti-pRB reactivity of the basal and spinous layer cells of the epidermis, and in the cellular compartment of the dermis 4 h after the initial exposure. The absence of nonspecific immunoreactivity in unirradiated skin probed with the IgG1 negative control antibody. Scale bar: 250 mm.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Effect of UV radiation upon the phosphorylation state of pRB in human skin. Unirradiated and irradiated skin slices were incubated in growth medium for 4 h and the polypeptides immunoprecipitated from cell lysates with the G3–245 anti-human pRB monoclonal antibody or IgG1 negative control antibody. Polypeptides were separated by 7.5% sodium dodecyl sulfate–polyacrylamide gel electrophoresis and the nitrocellulose membranes stained with RB-Ab2 anti-human pRB polyclonal antibody. Human skin (a), immunoprecipitated with the IgG1-negative control antibody showing the absence of nonspecific immuno- reactivity. Unirradiated skin (b), showing the presence of growth inhibitory hypophosphorylated pRB105 and hyperphosphorylated forms of pRB. Irradiated skin (c), showing the presence of growth inhibitory hypo- phosphorylated pRB105.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
Effect of UV and okadaic acid upon pRB expression in human keratinocytes. Unirradiated and irradiated asynchronous keratinocytes were incubated for 4 h in the presence of 0.5 nM or 5 mM okadaic acid and the cells immunolabeled with RB Ab2. Unirradiated keratinocytes (a), showing granular anti-pRB staining in the nuclei and nucleoli. Irradiated keratinocytes (b), showing a decrease in nuclear anti-pRB staining. Irradiated and 0.5 nM okadaic acid-treated keratinocytes (c), showing the localization of anti-pRB staining to the mitotic spindles. Irradiated and 5 mM okadaic acid-treated keratinocytes (d), showing the localization of pRB to the condensed chromatin of M-phase cells. Scale bar: 5 mm.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
Effect of UV and okadaic acid upon the phosphorylation state of pRB in human keratinocytes. Unirradiated and irradiated keratinocytes were incubated for 4 h in the absence and presence of 0.5 nM and 5 mM okadaic acid. The polypeptides from cell lysates were immunoprecipitated with the G3–245 anti-pRB monoclonal antibody or IgG1 negative control antibody and the membranes probed with the RB-Ab2 anti-pRB polyclonal antibody. Unirradiated keratinocytes (a), showing the presence of all forms of pRB. Control keratinocytes (b), immunoprecipitated with the IgG1-negative control antibody. Irradiated and 0.5 nM okadaic acid-treated keratinocytes (c), showing the presence of the growth inhibitory pRB105. Irradiated and 5 mM okadaic acid-treated keratinocytes (d) showing the presence of growth inhibitory pRB105 and all hyperphosphorylated forms of pRB.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Quantitation of pRB expression in human keratinocytes. The relative proportion of the hypophosphorylated pRB105 and hyperphosphorylated forms of pRB in irradiated and unirradiated keratinocytes were determined by scanning densitometry. Unirradiated keratinocytes (a), showing the presence of all forms of pRB. Irradiated and 0.5 nM okadaic acid-treated keratinocytes (b), showing the presence of growth inhibitory pRB105. Irradiated and 5 mM okadaic acid-treated keratinocytes (c), showing the presence of all forms of pRB.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions

7. Figure 6
Co-immunoprecipitation of pRB with PP1 from irradiated human keratinocytes. Irradiated keratinocytes were allowed to recover for 4 h at 37°C, and the cell lysates immunoprecipitated with the IgG1-negative control antibody or G3–245 anti-human pRB monoclonal antibody. The membranes were probed with the RB-Ab2 polyclonal antibody and anti-human PP1 monoclonal antibody. A 66 kDa bovine albumin prestained polypeptide molecular weight marker (a, e). Keratinocytes immunoprecipitated with the IgG1-negative control antibody showing the absence of nonspecific immunoreactivity (b, f). Polypeptides immunoprecipitated from irradiated keratinocytes with the anti-PP1 monoclonal antibody (c), showing the presence of growth inhibitory pRB105 and a 38 kDa polypeptide with anti-PP1 immunoreactivity. Irradiated keratinocytes (d), immunoprecipitated with the anti-pRB monoclonal antibody G3–245 and stained with the RB-Ab2 polyclonal antibody and anti-PP1 monoclonal antibody.
Journal of Investigative Dermatology  , 88-94DOI: ( /j x)
Copyright © 2000 The Society for Investigative Dermatology, Inc Terms and Conditions