Regulation of rRNA processing: a role for a unique GTPase

Recent findings by Karbstein et al. (2005 [this issue of Molecular Cell]) reveal that association of the preribosomal biosynthesis factors U3 snoRNA and Rcl1p is controlled by the GTPase Bms1p, suggesting that regulatory events are involved in the formation of ribosome biogenesis complexes.     

Yeast unravels epigenetic apoptosis control: deadly chat within a histone tail

An important paper by David Allis and colleagues (Ahn et al., 2006 [this issue of Molecular Cell]) describes a specific deacetylation/phosphorylation crosstalk at the histone H2B tail required for apoptosis induction in yeast, thus giving first insights into the poorly understood epigenetic regulation of cell death.     

Dephosphorylation shows SR proteins the way out

To address the role of the RS domain in shuttling and how it is differentially required for constitutive and alternative splicing, Lin et al. (2005 [in the November 11 issue of Molecular Cell]) employ an elegant somatic complementation system to reveal a novel phosphorylation-dependent mechanism regulating distinct recycling pathways for SR proteins during mRNP maturation.     

Movin' on up: adipocytes become regulators of nutrient homeostasis

By locally infecting epididymal adipocytes of obese diabetic mice with the uncoupling protein-1 transgene, Yamada et al. (2006[this issue of Cell Metabolism]) unexpectedly induce leptin sensitivity with hypophagia and improvement in abnormal glucose and lipid abnormalities.     

Obedient and wayward synaptic behavior

Synapse formation is a complex process that culminates in the linking up and locking in of pre- and postsynaptic membranes. Shen at al. (2004 [this issue of Cell]) begin to dissect the molecular instructions that govern target selection of pre- and postsynaptic membrane interactions.     

New insights into the combined Cockayne/xeroderma pigmentosum complex: human XPG protein can function in transcription factor stability

A new study provides evidence supporting a function for XPG protein in maintaining the integrity and function of TFIIH (Ito et al. [2007], this issue of Molecular Cell). This observation likely explains some of the clinical features of individuals with both defective DNA repair and development.     

Towards a splicing code

A combination of experimental and bioinformatics approaches leads Burge and colleagues (Wang et al., 2004 [this issue of Cell]) to a global view of how an RNA segment may be selected or avoided in mature mRNAs due to biased distributions of exonic enhancers and silencers, a process vital for genome evolution, developmental control, and disease onset.     

Coordinate regulation of an extended chromosome domain

Spitz et al (2003[this issue of Cell]) describe the properties of a novel cis-regulatory DNA element, the global control region (GCR), which regulates gene expression over distances of several hundred kilobases at the mouse HoxD complex. The GCR provides an explanation for the colinear genetic linkage and expression of individual Hox genes within developing limbs.     

A SIRTain role in pancreatic beta cell function

Genes formerly thought to be involved solely in the regulation of life span have increasingly become implicated in the regulation of metabolic processes. Moynihan et al.(2005[this issue of Cell Metabolism]) now demonstrate that increasing levels of Sirt1 in the pancreatic beta cells of mice result in a more efficient glucose handling due to enhanced glucose-stimulated insulin secretion.     

If the prophet does not come to the mountain: dynamics of signaling complexes in NF-kappaB activation

Recruitment of the NF-kappaB-activating IKK signaling complex to the TNF receptor is shown to be driven by induced binding of NEMO, a regulatory component of this complex, to K63-linked polyubiquitin chains attached to RIP1, a receptor-associated adaptor protein (Ea et al., 2006 [in a recent issue of Molecular Cell]; Li et al., 2006; Wu et al., 2006a).     

Swapping nucleotides, tuning Hsp70

Molecular chaperones such as heat shock protein 70 (Hsp70) are crucial for protein folding. Crystal structures of Hsp70 in a complex with the nucleotide exchange factor (NEF) Hsp110 reported in this issue of Cell (Polier et al., 2008) and in Molecular Cell (Schuermann et al., 2008) provide new insights into how NEF action specifies Hsp70 cellular function.     

Converting a motor to an anchor

Myosin VI can move along actin filaments to serve as a transport motor. It is also thought to anchor vesicles or proteins to actin. How these two diverse activities, which require very different modes of interaction with actin, are mediated is not understood. Using single molecule observations, Altman et al. (2004 [this issue of Cell]) demonstrate that load applied to myosin VI can convert this motor from a transporter to an anchor.     

Telomerase regulation at the telomere: a binary switch

Telomerase is known to preferentially elongate the shortest telomeres in a cell. Using an elegant yeast assay, Texeira et al. (2004 [this issue of Cell]) address what aspect of telomerase action is regulated by telomere length: the frequency or the extent of telomere elongation. They show that short telomeres are elongated more frequently than long telomeres, arguing that telomeres switch between two states, one that allows telomere extension and one that does not.     

Theme and variations: juxtamembrane regulation of receptor protein kinases

Huse et al. in this issue of Molecular Cell and Wybenga-Groot et al. in the September 21, 2001 issue of Cell present biochemical and structural studies that elucidate the roles of juxtamembrane phosphorylation in a receptor serine/threonine kinase, the type I receptor for transforming growth factor beta, and in a receptor tyrosine kinase, the ephrin receptor EphB2.     

Splicing from the outside in

A new study in this issue of Molecular Cell (Pleiss et al., 2007b) shows that changes in the environment rapidly alter the splicing efficiency of specific pre-mRNAs in yeast.     

Sam68 guest STARs in TNF-α signaling

In this issue of Molecular Cell, Ramakrishnan and Baltimore (2011) identify Sam68 as a TNFR1 docking protein required for proper activation of TNF-α signaling.     

Policing cells under stress: noncoding RNAs capture proteins in nucleolar detention centers

In this issue of Molecular Cell, Audas et al. (2012) demonstrate that a class of stress-induced noncoding RNAs immobilizes proteins in the nucleolus in response to a specific stimulus.     

Flicking the Warburg switch-tyrosine phosphorylation of pyruvate dehydrogenase kinase regulates mitochondrial activity in cancer cells

In this issue of Molecular Cell, Hitosugi et al. (2011) show that the switch from oxidative phosphorylation to glycolysis in cancer cells is regulated by tyrosine phosphorylation of PDHK1.