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Articles 1 - 4 of 4

Full-Text Articles in Cell Biology

Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw Jun 2018

Identification Of A Novel Invasion-Promoting Region In Insulin Receptor Substrate 2, Jose Mercado-Matos, Jenny Janusis, Sha Zhu, Samuel S. Chen, Leslie M. Shaw

University of Massachusetts Medical School Faculty Publications

Although the insulin receptor substrate (IRS) proteins IRS1 and IRS2 share considerable homology and activate common signaling pathways, their contributions to breast cancer are distinct. IRS1 has been implicated in the proliferation and survival of breast tumor cells. In contrast, IRS2 facilitates glycolysis, invasion, and metastasis. To determine the mechanistic basis for IRS2-dependent functions, we investigated unique structural features of IRS2 that are required for invasion. Our studies revealed that the ability of IRS2 to promote invasion is dependent upon upstream insulin-like growth factor 1 receptor (IGF-1R)/insulin receptor (IR) activation and the recruitment and activation of phosphatidylinositol 3-kinase (PI3K ...


Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech May 2018

Neuronal Modulation Of Brown Adipose Activity Through Perturbation Of White Adipocyte Lipogenesis, Adilson L. Guilherme, David J. Pedersen, Felipe Henriques, Alexander H. Bedard, Elizabeth Henchey, Mark Kelly, Kamal Rahmouni, Donald A. Morgan, Michael P. Czech

University of Massachusetts Medical School Faculty Publications

White adipose tissue (WAT) secretes factors to communicate with other metabolic organs to maintain energy homeostasis. We previously reported that perturbation of adipocyte de novo lipogenesis (DNL) by deletion of fatty acid synthase (FASN) causes expansion of sympathetic neurons within white adipose tissue (WAT) and the appearance of beige adipocytes. Here we report evidence that white adipocyte DNL activity is also coupled to neuronal regulation and thermogenesis in brown adipose tissue (BAT). Induced deletion of FASN in all adipocytes in mature mice (iAdFASNKO) enhanced sympathetic innervation and neuronal activity as well as UCP1 expression in both WAT and BAT. In ...


A Parental Requirement For Dual-Specificity Phosphatase 6 In Zebrafish, Jennifer M. Maurer, Charles G. Sagerstrom Mar 2018

A Parental Requirement For Dual-Specificity Phosphatase 6 In Zebrafish, Jennifer M. Maurer, Charles G. Sagerstrom

Open Access Articles

BACKGROUND: Signaling cascades, such as the extracellular signal-regulated kinase (ERK) pathway, play vital roles in early vertebrate development. Signals through these pathways are initiated by a growth factor or hormone, are transduced through a kinase cascade, and result in the expression of specific downstream genes that promote cellular proliferation, growth, or differentiation. Tight regulation of these signals is provided by positive or negative modulators at varying levels in the pathway, and is required for proper development and function. Two members of the dual-specificity phosphatase (Dusp) family, dusp6 and dusp2, are believed to be negative regulators of the ERK pathway and ...


Cbx4 Sumoylates Prdm16 To Regulate Adipose Tissue Thermogenesis, Qingbo Chen, Lei Huang, Dongning Pan, Lihua (Julie) Zhu, Yong-Xu Wang Mar 2018

Cbx4 Sumoylates Prdm16 To Regulate Adipose Tissue Thermogenesis, Qingbo Chen, Lei Huang, Dongning Pan, Lihua (Julie) Zhu, Yong-Xu Wang

Open Access Articles

Transcriptional co-activator Prdm16 controls brown fat development and white fat browning, but how this thermogenic function is modulated post-translationally is poorly understood. Here, we report that Cbx4, a Polycomb group protein, is a SUMO E3 ligase for Prdm16 and that Cbx4-mediated sumoylation of Prdm16 is required for thermogenic gene expression. Cbx4 expression is enriched in brown fat and is induced in adipose tissue by acute cold exposure. Sumoylation of Prdm16 at lysine 917 by Cbx4 blocks its ubiquitination-mediated degradation, thereby augmenting its stability and thermogenic function. Moreover, this sumoylation event primes Prdm16 to be further stabilized by methyltransferase Ehmt1. Heterozygous ...