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

The Apr 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(4):203 (2011)
  
• Ageing: Mitochondria and telomeres come together | PDF (155 KB)
  - Nat Rev Mol Cell Biol 12(4):204 (2011)
  There are mixed views as to what makes us age: one hypothesis proposes that ageing is caused by accumulating genotoxic stress provoked by the progressive loss of telomeres, which leads to replicative senescence and apoptosis, whereas another postulates that ageing is the result of progressive mitochondrial malfunction. A study by DePinho and colleagues now brings these two theories together by identifying a direct molecular link between telomere and mitochondrial dysfunction.
• Gene expression: Transcriptional activators do double-duty | PDF (165 KB)
  - Nat Rev Mol Cell Biol 12(4):205 (2011)
  mRNA processing is coupled to RNA polymerase II (RNAPII) transcription and involves interactions between the polyadenylation machinery, RNAPII and transcriptional activators. However, the mechanism is unclear and the full repertoire of interacting proteins is unknown.
• Finding gold in yellowing papers | PDF (130 KB)
  - Nat Rev Mol Cell Biol 12(4):205 (2011)
  It was on a trip north that I first glimpsed the riches that pass under our feet when we join the optimistic march of scientific progress. I had just started my laboratory and I imagined a world where a molecular cell biologist could carry out systematic loss-of-function screens on a whole-genome scale.
• Cell division: ESCRT'll tear us apart | PDF (165 KB)
  - Nat Rev Mol Cell Biol 12(4):206 (2011)
  At the end of cytokinesis, daughter cells split through abscission and go their separate ways. Endosomal sorting complex required for transport III (ESCRT-III), which is important for membrane fission during vesicle formation, is also present on the intercellular bridge that forms during cytokinesis and regulates abscission.
• Gene expression: Misreading the code | PDF (121 KB)
  - Nat Rev Mol Cell Biol 12(4):206 (2011)
  Ribosomes read the genetic code by matching the base-pairing of the mRNA codon to the correct tRNA anticodon. The discovery of tRNAs with mutations in the body of the tRNA (as opposed to in the anticodon) that result in aberrant decoding showed that tRNAs are not just scaffolds for amino acids and anticodons; the structure of the tRNA itself has a role in reading the code.
• Cell migration: Regulating the (missing) link | PDF (176 KB)
  - Nat Rev Mol Cell Biol 12(4):207 (2011)
  Wu et al. report in Cell that glycogen synthase kinase 3β (GSK3β) regulates an interaction between actin-crosslinking factor 7 (ACF7; also known as MACF1) and microtubules, further bolstering its status as a key mediator of cell polarity and cytoskeletal dynamics. They outline this mode of regulation using as a model the migration of stem cells (SCs) from a specific niche of the hair follicle, the bulge, in response to injury.
• Ageing: Staying alive without CRTC-1 | PDF (145 KB)
  - Nat Rev Mol Cell Biol 12(4):208 (2011)
  Activation of AMP-activated protein kinase (AMPK) or inactivation of the phosphatase calcineurin slows ageing in Caenorhabditis elegans, but the mechanism behind this was unknown. Mair et al.
• Molecular motors: Moving in a new direction | PDF (155 KB)
  - Nat Rev Mol Cell Biol 12(4):208 (2011)
  Kinesins are molecular motors that drive transport along microtubules, either towards the plus end or towards the minus end, depending on the position of their motor domain. Kinesins with an amino-terminal motor, such as Kinesin-5 family members, are thought to move towards microtubule plus-ends.
• Cell Signalling | Cell growth | Protein folding | PDF (100 KB)
  - Nat Rev Mol Cell Biol 12(4):208 (2011)
  Control of local Rho GTPase crosstalk by Abr Vaughan, E. M.et al. Curr. Biol. 21, 270–277 (2011)
• Cell cycle | Small RNAs | DNA repair | PDF (90 KB)
  - Nat Rev Mol Cell Biol 12(4):209 (2011)
  A Nup133-dependent NPC-anchored network tethers centrosomes to the nuclear envelope in prophase Bolhy, S.et al. J. Cell Biol. 192, 855–871 (2011)
• Signal integration in the control of shoot branching
  - Nat Rev Mol Cell Biol 12(4):211 (2011)
  Shoot branching is a highly plastic developmental process in which axillary buds are formed in the axil of each leaf and may subsequently be activated to give branches. Three classes of plant hormones, auxins, cytokinins and strigolactones (or strigolactone derivatives) are central to the control of bud activation. These hormones move throughout the plant forming a network of systemic signals. The past decade brought great progress in understanding the mechanisms of shoot branching control. Biological and computational studies have led to the proposal of two models, the auxin transport canalization-based model and the second messenger model, which provide mechanistic explanations for apical dominance.
• Ciliogenesis: building the cell's antenna
  - Nat Rev Mol Cell Biol 12(4):222 (2011)
  The cilium is a complex organelle, the assembly of which requires the coordination of motor-driven intraflagellar transport (IFT), membrane trafficking and selective import of cilium-specific proteins through a barrier at the ciliary transition zone. Recent findings provide insights into how cilia assemble and disassemble in synchrony with the cell cycle and how the balance of ciliary assembly and disassembly determines the steady-state ciliary length, with the inherent length-dependence of IFT rendering the ciliary assembly rate a decreasing function of length. As cilia are important in sensing and processing developmental signals and directing the flow of fluids such as mucus, defects in ciliogenesis and length control are likely to underlie a range of cilium-related human diseases.
• mRNA helicases: the tacticians of translational control
  - Nat Rev Mol Cell Biol 12(4):235 (2011)
  The translation initiation step in eukaryotes is highly regulated and rate-limiting. During this process, the 40S ribosomal subunit is usually recruited to the 5′ terminus of the mRNA. It then migrates towards the initiation codon, where it is joined by the 60S ribosomal subunit to form the 80S initiation complex. Secondary structures in the 5′ untranslated region (UTR) can impede binding and movement of the 40S ribosome. The canonical eukaryotic translation initiation factor eIF4A (also known as DDX2), together with its accessory proteins eIF4B and eIF4H, is thought to act as a helicase that unwinds secondary structures in the mRNA 5′ UTR. Growing evidence suggests that other helicases are also important for translation initiation and may promote the scanning processivity of the 40S subunit, synergize with eIF4A to 'melt' secondary structures or facilitate translation of a subset of mRNAs.
• PIWI-interacting small RNAs: the vanguard of genome defence
  - Nat Rev Mol Cell Biol 12(4):246 (2011)
  PIWI-interacting RNAs (piRNAs) are a distinct class of small non-coding RNAs that form the piRNA-induced silencing complex (piRISC) in the germ line of many animal species. The piRISC protects the integrity of the genome from invasion by 'genomic parasites' — transposable elements — by silencing them. Owing to their limited expression in gonads and their sequence diversity, piRNAs have been the most mysterious class of small non-coding RNAs regulating RNA silencing. Now, much progress is being made into our understanding of their biogenesis and molecular functions, including the specific subcellular compartmentalization of the piRNA pathway in granular cytoplasmic bodies.
• The p53 family: guardians of maternal reproduction
  - Nat Rev Mol Cell Biol 12(4):259 (2011)
  The p53 family of proteins consists of p53, p63 and p73, which are transcription factors that affect both cancer and development. It is now emerging that these proteins also regulate maternal reproduction. Whereas p63 is important for maturation of the egg, p73 ensures normal mitosis in the developing blastocyst. p53 subsequently regulates implantation of the embryo through transcriptional control of leukaemia inhibitory factor. Elucidating the cell biological basis of how these factors regulate female fertility may lead to new approaches to the control of human maternal reproduction.
• Computational morphodynamics of plants: integrating development over space and time
  - Nat Rev Mol Cell Biol 12(4):265 (2011)
  The emerging field of computational morphodynamics aims to understand the changes that occur in space and time during development by combining three technical strategies: live imaging to observe development as it happens; image processing and analysis to extract quantitative information; and computational modelling to express and test time-dependent hypotheses. The strength of the field comes from the iterative and combined use of these techniques, which has provided important insights into plant development.
• Correspondence: Conformational conversion and prion disease
  - Nat Rev Mol Cell Biol 12(4):273 (2011)
  Because of mechanistic similarities between prion propagation in mammals and fungi, Tuite and Serio recently proposed (The prion hypothesis: from biological anomaly to basic regulatory mechanism. Nature Rev. Mol. Cell Biol. 11, 823–833 (2010)
• Open chromatin in pluripotency and reprogramming
  - Nat Rev Mol Cell Biol 12(4):273 (2011)
  In the reference list for this article, reference 39 was incorrect. The reference should have been "Azuara V. et al. Chromatin signatures of pluripotent cell lines. Nature Cell Biol.8, 532–538 (2006)". The authors apologize for this error.
• Asymmetric cell division in land plants and algae: the driving force for differentiation
  - Nat Rev Mol Cell Biol 12(4):273 (2011)
  On page 183 of this article there was a mistake in the sentence "These include the genes encoding the transcription factors PROTODERMAL FACTOR 2 (PDF2)18,85 and ARABIDOPSIS THALIANA MERISTEM LAYER 1 (ATML1)18,86 and the LRR receptor-like kinase ARABIDOPSIS CRINKLY 4 (ACR4)87,88." ACR4 is not an LRR family protein. This has been corrected online.