PP2A:B56ε is required for eye induction and eye field separation

AbstractEye induction and eye field separation are the earliest events during vertebrate eye development. Both of these processes occur much earlier than the formation of optic vesicles. The insulin-like growth factor (IGF) pathway appears to be essential for eye induction, yet it remains unclear how IGF downstream pathways are involved in eye induction. As a consequence of eye induction, a single eye anlage is specified in the anterior neural plate. Subsequently, this single eye anlage is divided into two symmetric eye fields in response to Sonic Hedgehog (Shh) secreted from the prechordal mesoderm. Here, we report that B56ε regulatory subunit of protein phosphatase 2A (PP2A) is involved in Xenopus eye induction and subsequent eye field separation. We provide evidence that B56ε is required for the IGF/PI3K/Akt pathway and that interfering with the PI3K/Akt pathway inhibits eye induction. In addition, we show that B56ε regulates the Hedgehog (Hh) pathway during eye field separation. Thus, B56ε is involved in multiple signaling pathways and plays critical roles during early development

Live-cell single-molecule dynamics of PcG proteins imposed by the DIPG H3.3K27M mutation

Over 80% of diffuse intrinsic pontine gliomas (DIPGs) harbor a point mutation in histone H3.3 where lysine 27 is substituted with methionine (H3.3K27M); however, how the mutation affects kinetics and function of PcG proteins remains elusive. We demonstrate that H3.3K27M prolongs the residence time and search time of Ezh2, but has no effect on its fraction bound to chromatin. In contrast, H3.3K27M has no effect on the residence time of Cbx7, but prolongs its search time and decreases its fraction bound to chromatin. We show that increasing expression of Cbx7 inhibits the proliferation of DIPG cells and prolongs its residence time. Our results highlight that the residence time of PcG proteins directly correlates with their functions and the search time of PcG proteins is critical for regulating their genomic occupancy. Together, our data provide mechanisms in which the cancer-causing histone mutation alters the binding and search dynamics of epigenetic complexes

The Grizzly, February 11, 1991

Fraternity Pledging Returns Again • Wachtel Explains the Poverty of Affluence • The Changing War • Peer Educators and Community Service • Alumni Visit the Ballet • Study Abroad Memorable • A Valentine History • Side Winders • Dance Marathon • Get Shorty • Triumph of the Spirit • Gymnasts Fare Well at Ithaca, Reach Team Goal • Track Women Place Third at PAIAW Championships • Hoopsters Rounding Out Season • Fro Scores Point, Swimmers Wash Out Widener • Wrestlers Excel • Letters: Bring Becker Back; Praise From Florida; Oh no, Mr. Bill!; Respect Yourself and Your Major • War: A Personal Experience on the Homefront • Who Wants the Persian Gulf War? • The Mephisto of Calculus • This Spill No Mistakehttps://digitalcommons.ursinus.edu/grizzlynews/1270/thumbnail.jp

Elucidation of the mechanism and pathways promoting intestinal smooth muscle cell differentiation

The molecular mechanisms controlling smooth muscle differentiation are unknown. In an effort to elucidate these mechanisms, we examined the promoter region of a smooth muscle-specific gene, $\gamma$-smooth muscle isoactin. Our results demonstrate a role for serum response factor (SRF) in mediating the positive regulation of this gene. Because of the wide pattern expression of SRF, as well as its ability to complex with other transcription factors, it is likely that the SRF co-factors are responsible for the smooth muscle-specific expression of $\gamma$-smooth muscle isoactin. Additionally, we have preliminary evidence that BMP-4 and type IV collagen are able to promote intestinal smooth muscle cell (ISMC) differentiation. Furthermore, it appears that type IV collagen operates through a BMP-4-dependent manner. Together, this data significantly narrows the search for smooth muscle-specific transcription factors

Glycogen synthase kinase 3 controls migration of the neural crest lineage in mouse and Xenopus

Defects in neural crest development cause neurocristopathies and cancer, but what regulates this is unclear. Here, the authors show that glycogen synthase kinase 3 (GSK3) regulates migration of neural crest cells, as shown on genetic deletion of GSK3 in the mouse, and that this acts via anaplastic lymphoma kinase

JLK Inhibitors : Isocoumarin Compounds as Putative Probes to Selectively Target the gama-Secretase Pathway

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