Effect of monosodium glutamate on the histogenesis of bone marrow in mice

The effect of monosodium glutamate (MSG) on the histogenesis of bone and bone marrow of mice is studied. Intraperitoneal-subcutaneous injections and oral administration of the drug MSG induced marked repression in the ossification of developing endochondral bone with the persistence of cartilagenous elements and chondrocytes. A massive accumulation of adipose tissue accompanied by receded haemopoietic tissue within the bone marrow is observed in the MSG-treated animals. These pathological changes are attributed to the influence of the drug on the hydrolysis of enzyme alkaline phosphatase, glycolysis involved in the bone deposition or on the secretion of hormones responsible for bone resorption.     

Chilling injury in okra (Hibiscus esculentus L.) in relation to plant development and nitrogen metabolism

Summary Okra plants were exposed to chilling temperatures of 5° or 10°C for various periods up to 144 hours in a controlled environment room. Controls were maintained in a similar room at 25°C. Seedling plants which had developed five true leaves and plants in a preflowering condition with well developed buds were used. Results showed that injury occurred at both 5° and 10°C in plants at both growth stages. Seedling plants exposed at 5°C for 144 hours were killed while the older ones died back to the lower nodes. Eventually growth occurred from the buds at these nodes. In cases where the plants survived there was a delay in flowering and a decrease in the total number of flowers. Increased cold exposure resulted in an increased percentage dry matter. It appeared that increased dessication contributed to injury, but that atmospheric humidity itself had little relationship to injury. The insoluble nitrogen fraction did not show any great change. There was an increase in some amino acids, and it was noted that these were the same as those derived from pyruvate. The soluble protein fraction did not change. It was suggested that this lack of change might be a manifestation of the difference between plants that can be hardened and those that cannot.     

Light Quality Affects Protocorm-Like Body (PLB) Formation,Growth and Development of In Vitro Plantlets of Phalaenopsis pulcherrima

Biology Bulletin - Light-emitting diodes (LEDs) can be used as a useful alternative to the in vitro culture of various plant species, which not only accelerates plantlet growth and development but...     

Identification of a new gene locus for adolescent nephronophthisis, on chromosome 3q22 in a large Venezuelan pedigree

Nephronophthisis, an autosomal-recessive cystic kidney disease, is the most frequent monogenic cause for renal failure in childhood. Infantile and juvenile forms of nephronophthisis are known to originate from separate gene loci. We describe here a new disease form, adolescent nephronophthisis, that is clearly distinct by clinical and genetic findings. In a large, 340-member consanguineous Venezuelan kindred, clinical symptoms and renal pathology were evaluated. Onset of terminal renal failure was compared with that in a historical sample of juvenile nephronophthisis. Onset of terminal renal failure in adolescent nephronophthisis occurred significantly later (median age 19 years, quartile borders 16.0 and 25.0 years) than in juvenile nephronophthisis (median age 13.1 years, quartile borders 11.3 and 17.3 years; Wilcoxon test P=.0069). A total-genome scan of linkage analysis was conducted and evaluated by LOD score and total-genome haplotype analyses. A gene locus for adolescent nephronophthisis was localized to a region of homozygosity by descent, on chromosome 3q22, within a critical genetic interval of 2. 4 cM between flanking markers D3S1292 and D3S1238. The maximum LOD score for D3S1273 was 5.90 (maximum recombination fraction.035). This locus is different than that identified for juvenile nephronophthisis. These findings will have implications for diagnosis and genetic counseling in hereditary chronic renal failure and provide the basis for identification of the responsible gene.     

Consensus nomenclature for dyneins and associated assembly factors

Dyneins are highly complex, multicomponent, microtubule-based molecular motors. These enzymes are responsible for numerous motile behaviors in cytoplasm, mediate retrograde intraflagellar transport (IFT), and power ciliary and flagellar motility. Variants in multiple genes encoding dyneins, outer dynein arm (ODA) docking complex subunits, and cytoplasmic factors involved in axonemal dynein preassembly (DNAAFs) are associated with human ciliopathies and are of clinical interest. Therefore, clear communication within this field is particularly important. Standardizing gene nomenclature, and basing it on orthology where possible, facilitates discussion and genetic comparison across species. Here, we discuss how the human gene nomenclature for dyneins, ODA docking complex subunits, and DNAAFs has been updated to be more functionally informative and consistent with that of the unicellular green alga Chlamydomonas reinhardtii, a key model organism for studying dyneins and ciliary function. We also detail additional nomenclature updates for vertebrate-specific genes that encode dynein chains and other proteins involved in dynein complex assembly.

IntroductionDynein family motor proteins form multiple different dynein complexes in mammals, with important roles in a wide range of cellular functions (King, 2017; Osinka et al., 2019; Roberts, 2018). Dyneins can be broadly classified into two groups: cytoplasmic and axonemal. Dynein complexes “walk” toward the minus ends of microtubules; while doing so, they can transport a variety of cargoes within cells (Trokter et al., 2012). The motor activity of these complexes allows them to play key roles in enabling motility of whole cells, generating fluid flow across cell surfaces, and transporting organelles and other components within the cytoplasm.Dynein subunits are classified by mass into four categories: heavy (∼520 kD), intermediate (∼70 –140 kD), light intermediate (∼53–59 kD), and light (∼10–30 kD) chains (Pfister et al., 2006). The heavy and intermediate chains are specific to certain dynein complexes, while the light chains may be components of both cytoplasmic and axonemal dynein machinery, and in some cases, nondynein complexes. The light intermediate chains are present only in the cytoplasmic dynein class.Dynein-based movement is powered by the ATP-driven dynein heavy chain subunits (Schmidt and Carter, 2018). 15 genes in the human genome encode dynein heavy chains: 1 for each of the 2 cytoplasmic dynein complexes and 13 that encode heavy chain components of the various axonemal dynein complexes. A dynein-related gene, DNHD1 (dynein heavy chain domain 1) has been referred to as a “ghost gene”: it may be a remnant of an earlier duplication that has not decayed at a normal rate, as a truncated version might poison cytoplasmic dynein heavy chain dimerization and thus be lethal (Gibbons, 2018; Schmidt and Carter, 2018). DNHD1 is currently classified as an “orphan” dynein heavy chain-encoding gene (Kollmar, 2016) but may be in the process of becoming a pseudogene (Wickstead, 2018).Cytoplasmic dyneinsDynein 1 complexThe cytoplasmic dynein 1 complex (Table S1) is present throughout eukaryotes, with some notable exceptions such as green plants and red algae (Wickstead and Gull, 2007). It is involved in a wide variety of intracellular transport activities, transporting cargoes including chromosomes, mRNA, and protein complexes (Reck-Peterson et al., 2018). The dynein 1 complex also acts in cell division, helping to form and orient the mitotic spindle (Torisawa and Kimura, 2020), establish cell polarity (Lu and Gelfand, 2017), and position organelles (Allan, 2014; Oyarzún et al., 2019; Palmer et al., 2009).A dimer of DYNC1H1-encoded heavy chains forms the core of the cytoplasmic dynein 1 complex (Fig. 1 a) and acts as its ATPase motor (Palmer et al., 2009; Pfister et al., 2005). Each heavy chain contains six AAA+ domains, an antiparallel coiled-coil region with a microtubule-binding domain at its tip, and a C-terminal domain (Bhabha et al., 2016; Carter, 2013; Reck-Peterson et al., 2018; Roberts et al., 2013). Immediately N-terminal of the AAA1 domain is a linker that traverses the plane of the AAA ring and changes conformation during the ATPase cycle to drive motor activity. AAA1 exhibits ATP hydrolytic activity, acting as an ATPase and powering the dynein motor complex (Silvanovich et al., 2003), while nucleotide binding at several other AAA domains appears to modify how conformational change propagates through the AAA ring and affects microtubule-binding activity. The coordinated activity of both heavy chains within the dynein complex is required for processivity (Reck-Peterson et al., 2006).Open in a separate windowFigure 1.Cytoplasmic dynein complexes. (a) The cytoplasmic dynein 1 complex. The DYNC1H1 protein heavy chains have large globular heads at the C-termini that are composed of a ring of six AAA+ domains. The microtubule-binding domains are located at the tips of antiparallel coiled coils that derive from AAA4. The linker/N-terminal domains connect the AAA rings and the intermediate and light chains. (b) The cytoplasmic dynein 2 complex. The DYNC2H1 protein heavy chains power retrograde IFT and have the same general domain organization as DYNC1H1. However, the tails of the two heavy chains fold differently due to an asymmetry imposed by the two different intermediate chains: one is straight while the other forms a zigzag shape and interacts with the IFT-B train (Toropova et al., 2019). The linker/N-terminal domain connects the AAA ring and the intermediate and light chains. *It remains unknown whether the DYNLT2B protein forms a homodimer or a heterodimer with another Tctex-type light chain. (c) Schematic showing the interaction between the dynein 1 and dynactin complexes. The adapter molecule affects the type of cargo bound; in this figure, the hook microtubule tethering protein 3 (HOOK3)–encoded protein is acting as a cargo adapter.The intermediate chains of metazoan dynein 1 connect it to another multi-subunit complex known as dynactin (Loening et al., 2020). Dynactin is built around a filament of the protein encoded by ACTR1A (actin-related protein 1A). It activates dynein and regulates its binding to vesicles and organelles to be transported (Ketcham and Schroer, 2018). A coiled coil–containing cargo adaptor protein is required for dynein 1 activation (Fig. 1 c). A single adaptor protein sandwiches between dynactin and dynein, where it interacts with the dynein heavy chain tails and the light intermediate chain and along the length of the dynactin complex (Gonçalves et al., 2019; Reck-Peterson et al., 2018). There are currently ≥12 known cargo adaptor proteins, which are encoded by HOOK1, HOOK2, HOOK3, BICD2, BICDL1, BICDL2, RAB11FIP3, RASEF, CRACR2A, NIN, NINL, and SPDL1 (Barisic et al., 2010; Casenghi et al., 2005; Dona et al., 2015; Gonçalves et al., 2019; Horgan et al., 2010; Lee et al., 2018; Loening et al., 2020; Olenick et al., 2016; Vallee et al., 2021; Wang et al., 2019). Other protein cofactors may also be required for dynein recruitment to their cargoes. For example, the protein encoded by PAFAH1B1 (platelet activating factor acetylhydrolase 1b regulatory subunit 1; HUGO Gene Nomenclature Committee [HGNC] ID: 8574), also published using the alias LIS1 (lissencephaly 1) is required along with dynactin and BICD2 for dynein 1 to traffic many cargoes, such as nuclei, along microtubules (Faulkner et al., 2000; Splinter et al., 2012). LIS1 has most recently been suggested to stabilize the “open” conformation of cytoplasmic dynein 1 such that the heavy chains are able to undergo a mechanochemical cycle and cannot adopt the autoinhibited or “closed” state where movement of key mechanical elements is abrogated by interactions between heavy chains (Markus et al., 2020).The dynein light chains can be divided into three subfamilies: the t-complex associated (Tctex)–type family (encoded by DYNLT1, DYNLT2, DYNLT2B, DYNLT3, DYNLT4, and DYNLT5), the LC8-type family (encoded by DYNLL1, DYNLL2, and DNAL4), and the roadblock-type family (encoded by DYNLRB1 and DYNLRB2; Bowman et al., 1999; King et al., 1998; King et al., 1996; King and Patel-King, 1995). Most of these protein chains can be found in both cytoplasmic dynein complexes: the exceptions are DYNLT2, which is an axonemal dynein subunit; DYNLT2B, which is found in the dynein 2 complex and the I1/f inner dynein arm (IDA); DYNLT4 and DYNLT5, which are not well characterized; and DNAL4, which is present only in outer dynein arms (ODAs).Several proteins originally identified as dynein light chains are also found in numerous multimeric complexes unrelated to dyneins and appear to act as general dimerization engines or hubs (Williams et al., 2018). The LC8-type light chains (DYNLL1 and DYNLL2) are present in many enzymes including myosin V (Benashski et al., 1997; Espindola et al., 2000) and neuronal nitric oxide synthase (Jaffrey and Snyder, 1996). They also play a role in regulating apoptosis via an interaction with the BCL2 family protein encoded by BCL2L11 (Puthalakath et al., 1999). The DYNLT1 protein has reported roles in actin remodeling and neurite outgrowth (Chuang et al., 2005) and hypocretin signaling (Duguay et al., 2011). DYNLRB1 interacts with Rab6 family member proteins in the Golgi apparatus (Wanschers et al., 2008), and both roadblock-type dynein light chains are reportedly involved in a TGFβ signaling pathway (Jin et al., 2009).Dynein 2 complexCilia are highly complex microtubule-based organelles that extend from the cell surface and can be classified as either primary (or nonmotile) or motile (Satir and Christensen, 2008). Most eukaryotic cells, excluding blood cells and those actively dividing, have an associated primary or nonmotile cilium. These act as sensory organelles, detecting a broad range of signaling molecules (Kopinke et al., 2021; Mykytyn and Askwith, 2017; Saternos et al., 2020).The dynein 2 complex (also known as the intraflagellar transport [IFT] dynein or cytoplasmic dynein 1b in Chlamydomonas reinhardtii; Table S2) is found only in cells with associated cilia or flagella, where it locates within and around the base of these structures (Höök and Vallee, 2006). IFT trains are multiprotein complexes required for the assembly and function of cilia and flagella in eukaryotes (Dutcher, 2019; Wingfield et al., 2017). The anterograde IFT motor complex kinesin 2 moves IFT trains and associated cargoes plus the dynein 2 complex along microtubules, from the base to the tip of a cilium or flagellum (Toropova et al., 2019; Vuolo et al., 2020). The retrograde IFT motor complex dynein 2 transports IFT trains and associated factors from the tip back to the base (Hou and Witman, 2015; Pazour et al., 1998). The dynein 2 complex is required for the assembly of cilia and flagella (Pazour et al., 1999; Pfister et al., 2006) and also has key roles in ciliary signaling functions (Vuolo et al., 2020).The core of dynein 2 is composed of a dimer of two DYNC2H1-encoded heavy chains (Fig. 1 b). The tails of these identical heavy chains are directed into two different conformations by the other subunits in the complex (Toropova et al., 2019). Each heavy chain is stabilized by its interaction with a DYNC2LI1-encoded protein subunit. The C-terminal helix of one of these light intermediate subunits associates with a DYNC2I1 (previously WDR60)-encoded protein with a DYNLRB-encoded subunit, to enforce a distinct conformation on one heavy chain (Toropova et al., 2019; Vuolo et al., 2020).The DYNC2I1- and DYNC2I2-encoded intermediate chains bind the heavy chains via their C-terminal β-propeller domains. The N-terminal regions of these intermediate chains are dimerized by three DYNLL1/2 dimers and one of each of the other light chain dimers: DYNLT1/3, DYNLRB1/2, and DYNLT2B (Toropova et al., 2019). The DYNLT2B-encoded light chain is a unique accessory component of the dynein 2 complex. Whether it forms a homodimer or heterodimer with another light chain remains to be confirmed, although there is evidence to suggest that, unlike the other light chains, the DYNLT2B subunit may be monomeric (DiBella et al., 2001). Recent structural studies of Tetrahymena ODAs have revealed a Tctex-family heterodimer (Rao et al., 2021).Axonemal dyneinsMotile cilia (sometimes termed flagella when they occur singly or in small numbers on a cell) are more restricted to certain cell types. Their movement enables sperm to swim (Linck et al., 2016), respiratory cilia on epithelial cells to sweep away mucus containing trapped pathogens (Hansson, 2019), and oviduct epithelial cells to waft an ovum along a fallopian tube toward the uterus (Spassky and Meunier, 2017). Multiciliated cells in the brain help move the cerebrospinal fluid and also influence neuronal migration (Brooks and Wallingford, 2014). In the male reproductive tract, the epithelial cells of the efferent ducts are densely covered with multiple motile cilia necessary for the transport of sperm cells (Aprea et al., 2021a). Motility of nodal cilia in the embryonic left–right organizer is necessary for the determination of correct left–right body asymmetry (Nonaka et al., 1998).An axoneme is the microtubule superstructure core of the cilium and contains many tightly associated components. A motile cilium has a highly conserved “9 + 2” structure: 9 microtubule doublets that surround a central pair of 2 microtubule singlets (the “central apparatus”; Fig. 2). Axonemal dyneins are the motor complexes that drive a sliding motion between ciliary doublet microtubules, enabling movement. Motile cilia have IDAs and ODAs and radial spokes that are thought to be involved in signal transduction between the central pair and the outer microtubule ring (Ishikawa, 2017). Nonmotile cilia have only the outer doublet ring and have a 9 + 0 microtubule arrangement, although the number of outer doublets decreases and their arrangement changes beyond the proximal part of the cilium (Kiesel et al., 2020).Open in a separate windowFigure 2.Axonemal dynein complexes. (a) Axonemal ODA. The blue text denotes subunits found in ODA complexes in respiratory cilia, and red text denotes subunits found in ODA complexes in sperm flagella. (b) Axonemal inner arm I1/f complex subunits (IDA). (c) Monomeric IDAs. Each inner arm species is constructed around a distinct monomeric heavy chain associated with an actin monomer and either DNALI1 or centrin; species d contains two additional components. In most cases, the precise equivalence between the human and C. reinhardtii monomeric heavy chain species is uncertain.The ODAs (Table S3 and Fig. 2 a) and IDAs (Table S4 and Table S5, and Fig. 2, b and c) in motile cilia are arranged in two rows with a complex 96-nm repeat organization. They are permanently attached to the A-tubule of one outer doublet microtubule (see Fig. 3, a and b) and transiently interact in an ATP-dependent manner with the B-tubule of the adjacent doublet to generate a sliding force (King, 2017). IDAs with a single heavy chain are termed monomeric (Table S4), while the I1/f IDA (Table S5) is dimeric, with two nonidentical heavy chains. These different types of dyneins vary in terms of their enzymatic and motor properties, likely reflecting their precise roles in the generation of ciliary motility (King, 2017).Open in a separate windowFigure 3.Organization of a mammalian motile cilium. (a) The diagram illustrates the general 9 + 2 microtubule arrangement within the ciliary axoneme. The inner and outer rows of dynein arms generate the force required for ciliary beating. The N-DRC complex is a key regulatory structure that interconnects the doublet microtubules. The radial spokes regulate the beat of cilia by transducing signals between the doublets and the central microtubule pair. (b) Tomographic image of an averaged 96-nm repeat for a single human ciliary doublet microtubule, revealing the microtubule-associated dynein arms, N-DRC, and radial spoke. The scale bar represents 25 nm. This image was generated by Jason Schrad (Nicastro laboratory) using data from Lin et al. (2014). (c and d) Cross-section (c) and longitudinal (d) views of the 48-nm repeat organization of a bovine doublet microtubule. The components of the ODA-DC are individually colored and indicated. This ribbon diagram was generated with the PyMol molecular graphics system (Schrödinger) using Protein Data Bank accession no. 7RRO (Gui et al., 2021).ODA docking complex (ODA-DC)The correct functioning of cilia and flagella in most eukaryotes is dependent on the ODA chains attaching to the outer doublet microtubules at 24-nm intervals (Dean and Mitchell, 2015; King, 2017). The ODA-DC facilitates binding and may also play a role in regulating the activity of the ODAs (Takada et al., 2002). The ODA-DC in C. reinhardtii consists of three protein subunits, encoded by DCC1 (DC1), DCC2 (DC2), and DLE3 (DC3). In mammals, it consists of five protein subunits (Gui et al., 2021) encoded by five genes, now named ODAD1, ODAD2, ODAD3, ODAD4, and CLXN (calaxin; Fig. 2 a and Fig. 3, b and c). CLXN (previously EFCAB1) has been assigned the alias symbol ODAD5, and authors may refer to it as such in publications if they wish, referencing the approved gene symbol at least once to aid data retrieval. Only ODAD1 and ODAD3 have orthologues in C. reinhardtii (DCC2 and DCC1, respectively).Dynein axonemal assembly factors (DNAAFs)Genes encoding proteins that act as axonemal dynein assembly factors are named using the root symbol DNAAF. These proteins play an important role in the preassembly of IDAs and ODAs in the cytoplasm before their transport to cilia (Fabczak and Osinka, 2019; King, 2021).Historically, the DNAAF root has been used only for proteins directly involved in the preassembly of axonemal dynein arms in the cytoplasm. We wrote to authors who have published on the genes that we are reporting in this publication as newly updated DNAAFs (see their symbols in bold in Table S6) and discussed this issue with our specialist advisors for this gene group (https://www.genenames.org/data/genegroup/#!/group/1627). This effort resulted in an agreement to use the term “DNAAF” more broadly. Therefore, a DNAAF symbol can now also be assigned to genes encoding proteins that play a role in trafficking dynein arms from the cytoplasm to cilia.Association with human phenotypesHumans have four described cilia types, and defects in all types are associated with various diseases: motile 9 + 2 cilia (e.g., respiratory cilia, ependymal cilia, sperm flagella); motile 9 + 0 cilia (e.g., nodal cilia); nonmotile 9 + 2 cilia (e.g., the kinocilium of hair cells and the proximal region of olfactory cilia); and nonmotile 9 + 0 cilia (e.g., renal monocilia and the connecting cilia of photoreceptor cells). Cilia are located on almost all polarized cell types of the human body; therefore, cilia-related disorders (ciliopathies) affect many organ systems (Fliegauf et al., 2007). Genetic mutations that impair cilia and/or flagella beating cause a heterogeneous group of rare disorders referred to as motile ciliopathies (Wallmeier et al., 2020). The pathogenic mechanisms, clinical symptoms, and severity of the diseases depend on the specific affected genes and the tissues in which they are expressed. Defects in ependymal cilia can result in hydrocephalus. Reduced fertility can be due to defective cilia in the fallopian tubes or the efferent ducts as well as sperm flagella. The malfunction of motile monocilia on the left–right organizer during early embryonic development can lead to laterality defects such as situs inversus and heterotaxy. Severe impairment of mucociliary clearance in the respiratory tract leads to chronic bronchial problems. Primary ciliary dyskinesia (PCD), which can present with a variety of these features, is the most common motile ciliopathy.The genetic disorder PCD is heterogeneous and has been linked to variants in genes encoding dyneins, axonemal dynein assembly factors, and ODA-DC subunits (Wallmeier et al., 2020). PCD-associated phenotypes include chronic respiratory problems, recurrent middle ear infections, male infertility, and subfertility in females (Leigh et al., 2019). Roughly 50% of PCD patients are diagnosed with Kartagener syndrome, a subtype defined by a triad of symptoms: chronic sinusitis, bronchiectasis, and situs inversus, where the positions of major body organs are reversed (Zariwala et al., 2011). Situs inversus totalis is observed when all thoracic and abdominal viscera are reversed; individuals with situs inversus or situs ambiguus show more variable organ positioning (seen in ≥6% of PCD cases; Kennedy et al., 2007; Sempou and Khokha, 2019).Table 1.Human phenotypes associated with variants of genes encoding dyneins and dynein-associated proteins

A molecular beacon assay for monitoring RNA splicing

Small molecule targeting of self-splicing RNAs like group I and II introns has been limited in part by the lack of a universal high-throughput screening platform for studies of splicing inhibition and kinetics. Here, we present the development of a molecular beacon assay for monitoring the accumulation of spliced exons during RNA splicing reactions. In this case, we applied it to the autocatalyzed reaction of the H.c.LSU group II intron found in the mitochondria of the pathogenic dimorphic fungus Histoplasma capsulatum. We find that a molecular beacon with the loop length of 18 nucleotides selectively recognizes ligated exons formed during self-splicing and exhibits high fluorescent signal upon binding of its target. We demonstrate that the fluorescent assay using molecular beacons can be successfully applied to kinetic characterization of the splicing reaction and determination of inhibition constants for small molecules. The results presented herein offer support for a molecular beacon approach to identifying small molecule inhibitors of intron splicing.     

Osteosarcoma cells induce endothelial cell proliferation during neo‐angiogenesis

Understanding the mechanisms inducing endothelial cell (EC) proliferation following tumor microenvironment stimuli may be important for the development of antiangiogenic therapies. Here, we show that cyclin‐dependent kinase 2 and 5 (Cdk2, Cdk5) are important mediators of neoangiogenesis in in vitro and in vivo systems. Furthermore, we demonstrate that a specific Yin Yang 1 (YY1) protein‐dependent signal from osteosarcoma (SaOS) cells determines proliferation of human aortic endothelial cells (HAECs). Following tumor cell stimuli, HAECs overexpress Cdk2 and Cdk5, display increased Cdk2 activity, undergo enhanced proliferation, and form capillary‐like structures. Moreover, Roscovitine, an inhibitor of Cdks, blunted overexpression of Cdk2 and Cdk5 and Cdk2 activity induced by the YY1‐dependent signal secreted by SaOS cells. Furthermore, Roscovitine decreased HAEC proliferation and angiogenesis (the latter by 70% in in vitro and 50% in in vivo systems; P < 0.01 vs. control). Finally, the finding that Roscovitine triggers apoptosis in SaOS cells as well as in HAECs by activating caspase‐3/7 indicates multiple mechanisms for the potential antitumoral effect of Roscovitine. Present work suggests that Cdk2 and Cdk5 might be pharmacologically accessible targets for both antiangiogenic and antitumor therapy. J. Cell. Physiol. 228: 846–852, 2013. © 2012 Wiley Periodicals, Inc.     

Identification of the human ortholog of the t-complex-encoded protein TCTE3 and evaluation as a candidate gene for primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a heterogeneous autosomal recessive disease that is caused by impaired ciliary and flagellar functions. About 50% of PCD patients show situs inversus, denoted as Kartagener syndrome. In most cases, axonemal defects in cilia and sperm tails can be demonstrated by electron microscopy, i.e. PCD patients often lack inner and/or outer dynein arms in their sperm tails and cilia, supporting the hypothesis that mutations in dynein genes may cause PCD. In order to identify novel PCD genes we have isolated the human ortholog of the murine TCTE3 gene. The human TCTE3 gene encodes a dynein light chain and shares high similarity to dynein light chains of other species. The TCTE3 gene is expressed in tissues containing cilia or flagella, it is composed of four exons and located on chromosome 6q25-->q27. To elucidate the role of TCTE3 as a candidate gene for PCD a mutational analysis of thirty-six PCD patients was performed. We detected five polymorphisms in the coding sequence and in the 5' UTR of the TCTE3 gene. In one patient a heterozygous nucleotide exchange was identified resulting in an arginine to isoleucine substitution at the amino acid level. However, this exchange was also detected in one control DNA. Our results indicate that mutations in the TCTE3 gene are not a main cause of primary ciliary dyskinesia.