MEDICAL SCIENCES Correction for “Abnormal integrin-mediated regulation of chronic myelogenous leukemia CD34+ cell proliferation: BCR/ABL up-regulates the cyclin-dependent kinase inhibitor, p27Kip, which is relocated to the cell cytoplasm and incapable of regulating cdk2 activity,” by Yuehua Jiang, Robert C. H. Zhao, and Catherine M. Verfaillie, which appeared in issue 19, September 12, 2000, of Proc Natl Acad Sci USA (97:10538–10543; first published September 5, 2000; 10.1073/pnas.190104497).
The authors wish to note the following: “We inadvertently inserted the Western blot from a different experiment (Western blot for Cdk2, following immunoprecipitation of Cdk2 from a different experiment), instead of the correct Western blot for Cdk4, following immunoprecipitation of Cdk4 for the study described in Fig. 3. The correct Western blot for Cdk4-IP/WB: Cdk4 has now been inserted as lane 3 of the figure. In addition, we have added a black line in the Cdk2 kinase assay as well as in the Cdk4-IP/WB: Cdk4 Western blot to indicate that a blank lane was removed. We apologize for any inconvenience this may have caused.” This error does not affect the conclusions of the article. The corrected figure and its legend appear below.
Fig. 3.
Elevated levels of p27Kip do not inhibit cdk2 or cdk4 activity. Proteins were extracted from 5–10 × 106 FN-A, FN-NA, PLL-A (not shown), and PLL-NA (not shown) CML or NL CD34+ cells. cdk2 and cdk4 were immunoprecipitated from 500 μg protein by using anti-cdk2 or anti-cdk4 antibodies, or control IgG and protein-G-agarose beads, separated by SDS/PAGE and blots probed with anti-cdk2 or anti-cdk4 and goat anti-mouse HRP antibodies. cdk2 and cdk4 activity was assayed by adding 5 μg histone or GST-Rb and 10 μCi [r-32P] to immune complexes. Reaction products were resolved by SDS/PAGE, and the gel was exposed to X-ray film. A representative example of three separate experiments is shown.