CBP histone acetyltransferase activity regulates embryonic neural differentiation in the normal and Rubinstein-Taybi syndrome brain
Authors: Jing Wang
Freda D Miller
Frederic Wondisford
David R Kaplan
Haoran Wang
Ian C G Weaver
Andrée Gauthier-Fisher
Ling He
John Yeomans
Journal: Developmental Cell (2010)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Epigenetic changes; Neural precursors; CREB binding protein (CBP); Rubinstein-Taybi syndrome (RTS); Cognitive dysfunction
Affiliations: Developmental and Stem Cell Biology Program, Hospital for Sick Children, 555 University Ave., Toronto, ON, Canada.

Abstract:  Increasing evidence indicates that epigenetic changes regulate cell genesis. Here, we ask about neural precursors, focusing on CREB binding protein (CBP), a histone acetyltransferase that, when haploinsufficient, causes Rubinstein-Taybi syndrome (RTS), a genetic disorder with cognitive dysfunction. We show that neonatal cbp(+/-) mice are behaviorally impaired, displaying perturbed vocalization behavior. cbp haploinsufficiency or genetic knockdown with siRNAs inhibited differentiation of embryonic cortical precursors into all three neural lineages, coincident with decreased CBP binding and histone acetylation at promoters of neuronal and glial genes. Inhibition of histone deacetylation rescued these deficits. Moreover, CBP phosphorylation by atypical protein kinase C zeta was necessary for histone acetylation at neural gene promoters and appropriate differentiation. These data support a model in which environmental cues regulate CBP activity and histone acetylation to control neural precursor competency to differentiate, and indicate that cbp haploinsufficiency disrupts this mechanism, thereby likely causing cognitive dysfunction in RTS. 

Retracted: No

PubPeer comments:
 I have noticed potential issues with some of the images: ![file] Some B-actin bands are duplicated in Figure 4. (note that the bands in the blue box are slightly larger in E, but they are identical). In Figure 6B, the first band For E12 is uniquely dark and uniform, and is extremely dissimilar from all other bands in the publication. , 
 Thank you for bringing this to our attention. In response, we would like to make three points about Figure 4E and F. First, we are unaware of any mistakes made in assembling the beta-actin controls for this figure either at the time of publication 11 years ago or at any time since. Nonetheless, we are actively tracking down the original data, something that has been made more difficult by the passage of time. Second, we would like to point out that the experiments in panels 4E and F were confirmed using a different and more quantitative approach, qPCR, as shown in Fig. 4G and I from the same paper, obtaining essentially the same results. Finally, we would be happy to repeat the experiment in question if we are unable to find the original data. This would be done by a different individual to ensure reproducibility. This commentator also had issues with the exposure of the top panel in Fig. 6B. We include below the original western blot image for these experiments. Please note that the published western blot shows a darker chemoluminescence image so that the reader can visualize band intensity in all lanes. Here, we have uploaded a lighter exposure of the blot showing the same lanes (boxed area on the top blot). At the bottom we include the original panel from the figure for comparison. Please also note that we showed another western blot in Fig. 1C of the same paper confirming that CBP is highest at E12 relative to later developmental stages, as is seen in the bottom panel of Fig. 6B below. Jing Wang, David Kaplan and Freda Miller ![file] , 
 #1 I agree that those bands look identical. I also have some concerns over the GFAP bands in lanes 4+5 and 7+8 (red boxes), which look very similar. With the contrast at max, there are some differences in the bands, but with a lower contrast you can also see a boxy, geometric shape surrounding the bands (open image in full view). This raises the possibility that these bands were from two different exposures of the same probe, and they have been photoshopped into position. ![file] In general, and to allay these concerns, it would be useful to see the original blots. , 
 #2 Thank you for the swift response and for the clarification regarding the band in Figure 6B. I understand that finding originals may be difficult or impossible. I am hopeful that bringing to light this issue with the images will make for more careful image assembly in future. Best, #1 , 
 #1 #3 I agree with the concerns about Figure 4E, and hope the authors are able to find the originals. *** Inverted, contrast enhanced ![file] , 
 After considerable effort to find original data imaging (B-actin) for Figures 4E and 4F, we fortunately found the original image of B-actin for Figures 4E and 4F (please see below panel A). These images were not modified in any manner. Over the past 11 years the gel images have degraded and the relative intensity of the bands has significantly diminished and become less sharp. However, they still reflect the true original images of B-actin for Figures 4E and 4F. When we magnify the bands in question in Figures 4E and 4F, the bands are qualitatively different (please see below panel B). In particular, notice when comparing the  I or  A bands with each other in panel B, with an additional 500% magnification in ppt, they are similar but differ qualitatively. We would be happy to have an independent reviewer rather than ourselves or those affiliated with or contributing to PeerPub attest to this. ![file] ![file] ,