Hot off the presses! Mar 01 Nat Rev Mol Cell Biol

The Mar 01 issue of the Nat Rev Mol Cell Biol is now up on Pubget (About Nat Rev Mol Cell Biol): if you're at a subscribing institution, just click the link in the latest link at the home page. (Note you'll only be able to get all the PDFs in the issue if your institution subscribes to Pubget.)

Latest Articles Include:

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  - Nat Rev Mol Cell Biol 12(3):133 (2011)
  
• Cancer biology: Role of nuclear PTEN revealed | PDF (174 KB)
  - Nat Rev Mol Cell Biol 12(3):134 (2011)
  In the cytoplasm, the tumour suppressor protein phosphatase and tensin homologue (PTEN) dephosphorylates phosphoinositide-3,4,5-triphosphate to inhibit phosphoinositide 3-kinase (PI3K)–AKT signalling, cell growth and cell survival. Nuclear PTEN also has a tumour-suppressive role, but its functions were unknown.
• The 'RNP bridge' between two worlds | PDF (149 KB)
  - Nat Rev Mol Cell Biol 12(3):135 (2011)
  I believe that the genetic code was the greatest discovery of the twentieth century. When I saw the recent paper by Reiter et al.
• Endocytosis: One ubiquitin does the trick | PDF (175 KB)
  - Nat Rev Mol Cell Biol 12(3):135 (2011)
  ESCRTs (endosomal sorting complexes required for transport) mediate cargo sorting to multivesicular bodies (MVBs), and this is primarily mediated by their ubiquitin-binding domains (UBDs). UBDs also mediate ESCRT ubiquitylation through a process known as coupled ubiquitylation, but whether this has a physiologically relevant effect on ESCRT function was unclear.
• Gene expression: RNAPII stands alone | PDF (152 KB)
  - Nat Rev Mol Cell Biol 12(3):136 (2011)
  The idea that mRNA splicing occurs co-transcriptionally makes sense given the long lengths of many eukaryotic genes. Furthermore, it has become increasingly apparent that splicing is itself regulated by transcription, as the rate of polymerase elongation can influence the regulation of alternative exon inclusion.
• Autophagy: ESCRTing proteins for microautophagy | PDF (186 KB)
  - Nat Rev Mol Cell Biol 12(3):136 (2011)
  In eukaryotes, cytosolic components can be delivered to lysosomes for degradation through macroautophagy, chaperone-mediated autophagy (CMA) or microautophagy. Autophagic cargo can also be transported to a type of late endosome known as a multivesicular body (MVB).
• Cytoskeleton: SAS-6 turns a cartwheel trick | PDF (236 KB)
  - Nat Rev Mol Cell Biol 12(3):137 (2011)
  Centrioles provide the core structure for generating centrosomes, cilia and flagella. They themselves undergo a complex biogenesis process, which begins with the formation of a 'cartwheel' structure, in which nine 'spokes' radiate from a central ring-like hub.
• Gene expression: Teasing out transcription | PDF (139 KB)
  - Nat Rev Mol Cell Biol 12(3):138 (2011)
  The discovery a few years ago that transcription can initiate in a bidirectional manner, with many antisense transcripts being quickly degraded, opened our eyes to the extent to which transcriptional control is exerted after initiation. So far, analysis of this has been limited owing to the difficulty of detecting nascent transcripts in vivo.
• DNA replication: Partnering to unwind | PDF (144 KB)
  - Nat Rev Mol Cell Biol 12(3):138 (2011)
  Accurate DNA replication is critical for maintaining genomic stability and preventing the accumulation of cancer-causing mutations that are characteristic of disorders such as Fanconi's anaemia (FA) and Bloom's syndrome (BS). Thirteen causative genes for FA have been identified, including the gene encoding the FA group J (FANCJ) helicase.
• Nuclear transport | Post-translational modification | Membrane trafficking | PDF (126 KB)
  - Nat Rev Mol Cell Biol 12(3):139 (2011)
  Nuclear import of an intact preassembled proteasome particle Savulescu, A. F.et al. Mol. Biol. Cell2 Feb 2011 (doi:10.1091/mbc.E10-07-0595)
• CREB and the CRTC co-activators: sensors for hormonal and metabolic signals
  - Nat Rev Mol Cell Biol 12(3):141 (2011)
  The cyclic AMP-responsive element-binding protein (CREB) is phosphorylated in response to a wide variety of signals, yet target gene transcription is only increased in a subset of cases. Recent studies indicate that CREB functions in concert with a family of latent cytoplasmic co-activators called cAMP-regulated transcriptional co-activators (CRTCs), which are activated through dephosphorylation. A dual requirement for CREB phosphorylation and CRTC dephosphorylation is likely to explain how these activator–co-activator cognates discriminate between different stimuli. Following their activation, CREB and CRTCs mediate the effects of fasting and feeding signals on the expression of metabolic programmes in insulin-sensitive tissues.
• HTRA proteases: regulated proteolysis in protein quality control
  - Nat Rev Mol Cell Biol 12(3):152 (2011)
  Controlled proteolysis underlies a vast diversity of protective and regulatory processes that are of key importance to cell fate. The unique molecular architecture of the widely conserved high temperature requirement A (HTRA) proteases has evolved to mediate critical aspects of ATP-independent protein quality control. The simple combination of a classic Ser protease domain and a carboxy-terminal peptide-binding domain produces cellular factors of remarkable structural and functional plasticity that allow cells to rapidly respond to the presence of misfolded or mislocalized polypeptides.
• Moving into the cell: single-molecule studies of molecular motors in complex environments
  - Nat Rev Mol Cell Biol 12(3):163 (2011)
  Much has been learned in the past decades about molecular force generation. Single-molecule techniques, such as atomic force microscopy, single-molecule fluorescence microscopy and optical tweezers, have been key in resolving the mechanisms behind the power strokes, 'processive' steps and forces of cytoskeletal motors. However, it remains unclear how single force generators are integrated into composite mechanical machines in cells to generate complex functions such as mitosis, locomotion, intracellular transport or mechanical sensory transduction. Using dynamic single-molecule techniques to track, manipulate and probe cytoskeletal motor proteins will be crucial in providing new insights.
• Asymmetric cell division in land plants and algae: the driving force for differentiation
  - Nat Rev Mol Cell Biol 12(3):177 (2011)
  Asymmetric cell division generates two cells with different fates and has an important role in plant development. It produces distinct cell types and new organs, and maintains stem cell niches. To handle the constraints of having immobile cells, plants possess numerous unique features to obtain asymmetry, such as specific regulators of intrinsic polarity. Although several components have not yet been identified, new findings, together with knowledge from different developmental systems, now allow us to take an important step towards a mechanistic overview of asymmetric cell division in plants and algae. Strikingly, several key regulators are used for different developmental processes, and common mechanisms can be recognized.
• Adhesion molecule signalling: not always a sticky business
  - Nat Rev Mol Cell Biol 12(3):189 (2011)
  The signalling activity of cell adhesion molecules (CAMs) such as cadherins, immunoglobulin-like CAMs or integrins has long been considered to be a direct consequence of their adhesive properties. However, there are physiological and pathological processes that reduce or even abrogate the adhesive properties of CAMs, such as cleavage, conformational changes, mutations and shedding. In some cases these 'adhesion deficient' CAMs still retain signalling properties through their cytoplasmic domains and/or their mutated or truncated extracellular domains. The ability of CAMs to activate signal transduction cascades in the absence of cell adhesion significantly extends their range of biological activities.
• DNA damage response in adult stem cells: pathways and consequences
  - Nat Rev Mol Cell Biol 12(3):198 (2011)
  In contrast to postmitotic or short-lived somatic cells, tissue-specific stem cells must persist and function throughout life to ensure tissue homeostasis and repair. The enormous functional demands and longevity of stem cells raises the possibility that stem cells might be uniquely equipped to maintain genomic integrity in ways different than somatic cells. Indeed, evidence suggests that stem cell compartments possess unique properties that combine to either limit or, in some instances, accelerate DNA damage accrual.