SNX27–Retromer directly binds ESCPE-1 to transfer cargo proteins during endosomal recycling

Coat complexes coordinate cargo recognition through cargo adaptors with biogenesis of transport carriers during integral membrane protein trafficking. Here, we combine biochemical, structural, and cellular analyses to establish the mechanistic basis through which SNX27-Retromer, a major endosomal cargo adaptor, couples to the membrane remodeling endosomal SNX-BAR sorting complex for promoting exit 1 (ESCPE-1). In showing that the SNX27 FERM (4.1/ezrin/radixin/moesin) domain directly binds acidic-Asp-Leu-Phe (aDLF) motifs in the SNX1/SNX2 subunits of ESCPE-1, we propose a handover model where SNX27-Retromer captured cargo proteins are transferred into ESCPE-1 transport carriers to promote endosome-to-plasma membrane recycling. By revealing that assembly of the SNX27:Retromer:ESCPE-1 coat evolved in a stepwise manner during early metazoan evolution, likely reflecting the increasing complexity of endosome-to-plasma membrane recycling from the ancestral opisthokont to modern animals, we provide further evidence of the functional diversification of yeast pentameric Retromer in the recycling of hundreds of integral membrane proteins in metazoans

Molecular mechanism for kinesin-1 direct membrane recognition

The cargo-binding capabilities of cytoskeletal motor proteins have expanded during evolution through both gene duplication and alternative splicing. For the light chains of the kinesin-1 family of microtubule motors, this has resulted in an array of carboxyl-terminal domain sequences of unknown molecular function. Here, combining phylogenetic analyses with biophysical, biochemical, and cell biology approaches, we identify a highly conserved membrane-induced curvature-sensitive amphipathic helix within this region of a subset of long kinesin light-chain paralogs and splice isoforms. This helix mediates the direct binding of kinesin-1 to lipid membranes. Membrane binding requires specific anionic phospholipids, and it contributes to kinesin-1\u2013dependent lysosome positioning, a canonical activity that, until now, has been attributed exclusively the recognition of organelle-associated cargo adaptor proteins. This leads us to propose a protein-lipid coincidence detection framework for kinesin-1\u2013mediated organelle transport

Preservation of the Bladder in Patients With Rhabdomyosarcoma

Purpose: To review the pathologic findings from children with gross residual rhabdomyosarcoma (RMS) of the bladder and compare the treatment outcome of those who underwent cystectomy with those who did not. Patients and Methods: Primary and follow-up records and pathology specimens for 28 patients with gross residual disease entered onto the Intergroup Rhabdomyosarcoma Study (IRS) III were reviewed. These patients were assigned to receive 20 weeks of multiagent induction chemotherapy and 4 weeks of radiotherapy. Future therapy decisions were based on clinical and histologic evaluation at 20 weeks. Results: All patients had a clinical and histologic response. Thirteen patients underwent cystectomy at intervals that ranged from 1.5 to 38 months after the start of therapy. All but one patient are alive and well without recurrence. Reasons for cystectomy included presumed evidence of tumor growth from imaging studies, findings at cystoscopy, or histologic interpretation of biopsies. In HE GOAL OF THE Intergroup Rhabdomyosarcoma Study (IRS) for patients with primary bladder or bladder/prostate rhabdomyosarcoma (RMS) is not only survival, but survival with an intact and functioning bladder.3 Retention of the bladder may also minimize some of the long-term problems of sexual dysfunction associated with cystectomy. The use of partial cystectomy has been fostered to attain this goal, but is applicable in a relatively limited number of cases. 4 5 Among patients in IRS III with gross residual disease after biopsy, subsequent cystectomies were performed most frequently in patients with intravesical primary tumors (43%), less often in those with prostatic primary tumors (36%), and least often in those with extravesical primary tumors that did not extend through the bladder wall (14%). Because more cystectomies were performed for intravesical primary tumors and subsequent biopsies more readily obtained at cystoscopy, this group was chosen for review. Pathologic review of primary and follow-up specimens was made, comparing findings between those patients who retained the bladder and those who underwent cystectomy. PATIENTS AND METHODS Patient Selection One hundred three patients were entered onto IRS III with primary tumors that involved the bladder between November 1984 and September 1988. There were 35 patients with positive biopsies from intravesical bladder sites, 24 with abdominal or pelvic masses with bladder attachment, and 44 with prostatic or bladder/prostate involvement. Among the 35 intravesical tumors, four were group I cases (no gross or microscopic residual disease after initial surgery) and all are living and well following partial cystectomy and chemotherapy. A single group II patient (microscopic residual disease) underwent cystectomy as primary therapy for an intravesical tumor that extended through the bladder wall to an abdominal mass. This patient died of pneumonia after 8 months of chemotherapy and radiotherapy. Two of 30 patients with group III disease died following 2 and 3 weeks of therapy from toxicity related to chemotherapy. The remaining 28 group III patients comprise the current study. Treatment After initial biopsy, patients with gross residual disease (group III) were scheduled to be treated with 20 weeks of induction chemo

Molecular dating of the teleost whole genome duplication (3R) is compatible with the expectations of delayed rediploidization

Vertebrate evolution has been punctuated by three whole genome duplication (WGD) events that have been implicated causally in phenotypic evolution, from the origin of phenotypic novelties to explosive diversification. Arguably the most dramatic of these is the 3R WGD event associated with the origin of teleost fishes which comprise more than half of all living vertebrate species. However, tests of a causal relationship between WGD and teleost diversification have proven difficult due to the challenge of establishing the timing of these phenomena. Here we show, based on molecular clock dating of concatenated gene alignments, that the 3R WGD event occurred in the early-middle Permian (286.18-267.20 Million years ago; Ma), 52.02-12.84 million years (Myr) before the divergence of crown- teleosts in the latest Permian-earliest Late Triassic (254.36-234.16 Ma) and long before the major pulses of teleost diversification in Ostariophysi and Percomorpha (56.37-100.17 Myr and at least 139.24-183.29 Myr later, respectively). The extent of this temporal gap between putative cause and effect precludes 3R as a deterministic driver of teleost diversification. However, these age constraints remain compatible with the expectations of a prolonged rediploidization process following WGD which, through the effects of chromosome rearrangement and gene loss, remains a viable mechanism to explain the evolution of teleost novelties and diversificatio

An estimate of the deepest branches of the tree of life from ancient vertically-evolving genes

Core gene phylogenies provide a window into early evolution, but different gene sets and analytical methods have yielded substantially different views of the tree of life. Trees inferred from a small set of universal core genes have typically supported a long branch separating the archaeal and bacterial domains. By contrast, recent analyses of a broader set of non-ribosomal genes have suggested that Archaea may be less divergent from Bacteria, and that estimates of inter-domain distance are inflated due to accelerated evolution of ribosomal proteins along the inter-domain branch. Resolving this debate is key to determining the diversity of the archaeal and bacterial domains, the shape of the tree of life, and our understanding of the early course of cellular evolution. Here, we investigate the evolutionary history of the marker genes key to the debate. We show that estimates of a reduced Archaea-Bacteria (AB) branch length result from inter-domain gene transfers and hidden paralogy in the expanded marker gene set. By contrast, analysis of a broad range of manually curated marker gene datasets from an evenly sampled set of 700 Archaea and Bacteria reveals that current methods likely underestimate the AB branch length due to substitutional saturation and poor model fit; that the best-performing phylogenetic markers tend to support longer inter-domain branch lengths; and that the AB branch lengths of ribosomal and non-ribosomal marker genes are statistically indistinguishable. Furthermore, our phylogeny inferred from the 27 highest-ranked marker genes recovers a clade of DPANN at the base of the Archaea and places the bacterial Candidate Phyla Radiation (CPR) within Bacteria as the sister group to the Chloroflexota

ATP synthase evolution on a cross-braced dated tree of life

The timing of early cellular evolution, from the divergence of Archaea and Bacteria to the origin of eukaryotes, is poorly constrained. The ATP synthase complex is thought to have originated prior to the Last Universal Common Ancestor (LUCA) and analyses of ATP synthase genes, together with ribosomes, have played a key role in inferring and rooting the tree of life. We reconstruct the evolutionary history of ATP synthases using an expanded taxon sampling set and develop a phylogenetic cross-bracing approach, constraining equivalent speciation nodes to be contemporaneous, based on the phylogenetic imprint of endosymbioses and ancient gene duplications. This approach results in a highly resolved, dated species tree and establishes an absolute timeline for ATP synthase evolution. Our analyses show that the divergence of ATP synthase into F- and A/V-type lineages was a very early event in cellular evolution dating35 back to more than 4Ga, potentially predating the diversification of Archaea and Bacteria. Our crossbraced, dated tree of life also provides insight into more recent evolutionary transitions including eukaryogenesis, showing that the eukaryotic nuclear and mitochondrial lineages diverged from their closest archaeal (2.67-2.19Ga) and bacterial (2.58-2.12Ga) relatives at approximately the same time, with a slightly longer nuclear stem-lineage

Forty-five–year follow-up of a childhood leukemia survivor: Serendipity or karma?

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34593/1/15_ftp.pd