scholarly journals A variant of Runx2 that differs from the bone isoform in its splicing is expressed in spermatogenic cells

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1862
Author(s):  
Satoru Kanto ◽  
Marcin Grynberg ◽  
Yoshiyuki Kaneko ◽  
Jun Fujita ◽  
Masanobu Satake

Background.Members of theRunxgene family encode transcription factors that bind to DNA in a sequence-specific manner. Among the three Runx proteins, Runx2 comprises 607 amino acid (aa) residues, is expressed in bone, and plays crucial roles in osteoblast differentiation and bone development. We examined whether theRunx2gene is also expressed in testes.Methods.Murine testes from 1-, 2-, 3-, 4-, and 10-week-old male mice of the C57BL/6J strain andW∕Wvstrain were used throughout the study. Northern Blot Analyses were performed using extracts form the murine testes. Sequencing of cDNA clones and 5′-rapid amplification of cDNA ends were performed to determine the full length of the transcripts, which revealed that the testicular Runx2 comprises 106 aa residues coding novel protein. Generating an antiserum using the amino-terminal 15 aa of Runx2 (Met1to Gly15) as an antigen, immunoblot analyses were performed to detect the predicted polypeptide of 106 aa residues with the initiating Met1. With the affinity-purified anti-Runx2 antibody, immunohistochemical analyses were performed to elucidate the localization of the protein. Furthermore, bioinformatic analyses were performed to predict the function of the protein.Results.ARunx2transcript was detected in testes and was specifically expressed in germ cells. Determination of the transcript structure indicated that the testicularRunx2is a splice isoform. The predicted testicular Runx2 polypeptide is composed of only 106 aa residues, lacks a Runt domain, and appears to be a basic protein with a predominantly alpha-helical conformation. Immunoblot analyses with an anti-Runx2 antibody revealed that Met1in the deduced open reading frame ofRunx2is used as the initiation codon to express an 11 kDa protein. Furthermore, immunohistochemical analyses revealed that the Runx2 polypeptide was located in the nuclei, and was detected in spermatocytes at the stages of late pachytene, diplotene and second meiotic cells as well as in round spermatids. Bioinformatic analyses suggested that the testicular Runx2 is a histone-like protein.Discussion.A variant ofRunx2that differs from the bone isoform in its splicing is expressed in pachytene spermatocytes and round spermatids in testes, and encodes a histone-like, nuclear protein of 106 aa residues. Considering its nuclear localization and differentiation stage-dependent expression, Runx2 may function as a chromatin-remodeling factor during spermatogenesis. We thus conclude that a singleRunx2gene can encode two different types of nuclear proteins, a previously defined transcription factor in bone and cartilage and a short testicular variant that lacks a Runt domain.


1999 ◽  
Vol 73 (5) ◽  
pp. 4524-4529 ◽  
Author(s):  
Victor van Berkel ◽  
Karen Preiter ◽  
Herbert W. Virgin ◽  
Samuel H. Speck

ABSTRACT Several viruses, including members of the gammaherpesvirus family, encode proteins that are secreted into the extracellular environment. We have identified an abundant 44-kDa secreted protein that is present in the supernatant of fibroblasts infected with murine gammaherpesvirus 68 (γHV68; also referred to as MHV-68) but not in that of uninfected fibroblasts. Sequence analysis of the amino terminus and of internal peptides revealed that this protein is encoded by the γHV68 M3 open reading frame (ORF). The amino-terminal sequence of the secreted protein starts at residue 25 of the M3 ORF, consistent with the first 24 residues functioning as a signal peptide. Northern blot analysis revealed a single abundant ∼1.4-kb early-late lytic transcript encoded by the M3 ORF. Analysis of a partial cDNA clone and subsequent analyses of products of rapid amplification of cDNA ends coupled with S1 nuclease protection assays demonstrate that the M3 protein is encoded by an unspliced, polyadenylated mRNA initiating at bp 7294 and terminating at bp 6007 of the γHV68 genome. The 3′ end of the M3 transcript maps 9 bp downstream of a consensus polyadenylation signal. Thus, the predicted M3 ORF is a functional gene that encodes an abundant secreted protein which is a candidate for interacting with host cellular receptors or cytokines.



1991 ◽  
Vol 11 (10) ◽  
pp. 5113-5124 ◽  
Author(s):  
H Wu ◽  
A B Reynolds ◽  
S B Kanner ◽  
R R Vines ◽  
J T Parsons

Transformation of cells by the src oncogene results in elevated tyrosine phosphorylation of two related proteins, p80 and p85 (p80/85). Immunostaining with specific monoclonal antibodies revealed a striking change of subcellular localization of p80/85 in src-transformed cells. p80/85 colocalizes with F-actin in peripheral extensions of normal cells and rosettes (podosomes) of src-transformed cells. Sequence analysis of cDNA clones encoding p80/85 revealed an amino-terminal domain composed of six copies of a direct tandem repeat, each repeat containing 37 amino acids, a carboxyl-terminal SH3 domain, and an interdomain region composed of a highly charged acidic region and a region rich in proline, serine, and threonine. The multidomain structure of p80/85 and its colocalization with F-actin in normal and src-transformed cells suggest that these proteins may associate with components of the cytoskeleton and contribute to organization of cell structure.



2000 ◽  
Vol 278 (6) ◽  
pp. C1200-C1211 ◽  
Author(s):  
Mark O. Bevensee ◽  
Bernhard M. Schmitt ◽  
Inyeong Choi ◽  
Michael F. Romero ◽  
Walter F. Boron

We screened rat brain cDNA libraries and used 5′ rapid amplification of cDNA ends to clone two electrogenic Na+-[Formula: see text] cotransporter (NBC) isoforms from rat brain (rb1NBC and rb2NBC). At the amino acid level, one clone (rb1NBC) is 96% identical to human pancreas NBC. The other clone (rb2NBC) is identical to rb1NBC except for 61 unique COOH-terminal amino acids, the result of a 97-bp deletion near the 3′ end of the open-reading frame. Using RT-PCR, we confirmed that mRNA from rat brain contains this 97-bp deletion. Furthermore, we generated rabbit polyclonal antibodies that distinguish between the unique COOH-termini of rb1NBC (αrb1NBC) and rb2NBC (αrb2NBC). αrb1NBC labels an ∼130-kDa protein predominantly from kidney, and αrb2NBC labels an ∼130-kDa protein predominantly from brain. αrb2NBC labels a protein that is more highly expressed in cortical neurons than astrocytes cultured from rat brain; αrb1NBC exhibits the opposite pattern. In expression studies, applying 1.5% CO2/10 mM [Formula: see text] to Xenopus oocytes injected with rb2NBC cRNA causes 1) pHi to recover from the initial CO2-induced acidification and 2) the cell to hyperpolarize. Subsequently, removing external Na+ reverses the pHi increase and elicits a rapid depolarization. In the presence of 450 μM DIDS, removing external Na+ has no effect on pHi and elicits a small hyperpolarization. The rate of the pHidecrease elicited by removing Na+ is insensitive to removing external Cl−. Thus rb2NBC is a DIDS-sensitive, electrogenic NBC that is predominantly expressed in brain of at least rat.



2001 ◽  
Vol 5 (3) ◽  
pp. 137-145 ◽  
Author(s):  
CLAUDIA R. VIANNA ◽  
THILO HAGEN ◽  
CHEN-YU ZHANG ◽  
ERIC BACHMAN ◽  
OLIVIER BOSS ◽  
...  

The cDNA of an uncoupling protein (UCP) homolog has been cloned from the swallow-tailed hummingbird, Eupetomena macroura. The hummingbird uncoupling protein (HmUCP) cDNA was amplified from pectoral muscle (flight muscle) using RT-PCR and primers for conserved domains of various known UCP homologs. The rapid amplification of cDNA ends (RACE) method was used to complete the cloning of the 5′ and 3′ ends of the open reading frame. The HmUCP coding region contains 915 nucleotides, and the deduced protein sequence consists of 304 amino acids, being ∼72, 70, and 55% identical to human UCP3, UCP2, and UCP1, respectively. The uncoupling activity of this novel protein was characterized in yeast. In this expression system, the 12CA5-tagged HmUCP fusion protein was detected by Western blot in the enriched mitochondrial fraction. Similarly to rat UCP1, HmUCP decreased the mitochondrial membrane potential as measured in whole yeast by uptake of the fluorescent potential-sensitive dye 3′,3-dihexyloxacarbocyanine iodide. The HmUCP mRNA is primarily expressed in skeletal muscle, but high levels can also be detected in heart and liver, as assessed by Northern blot analysis. Lowering the room’s temperature to 12–14°C triggered the cycle torpor/rewarming, typical of hummingbirds. Both in the pectoral muscle and heart, HmUCP mRNA levels were 1.5- to 3.4-fold higher during torpor. In conclusion, this is the first report of an UCP homolog in birds. The data indicate that HmUCP has the potential to function as an UCP and could play a thermogenic role during rewarming.



2007 ◽  
Vol 81 (22) ◽  
pp. 12210-12217 ◽  
Author(s):  
Greg Brennan ◽  
Yury Kozyrev ◽  
Toshiaki Kodama ◽  
Shiu-Lok Hu

ABSTRACT The TRIM5 family of proteins contains a RING domain, one or two B boxes, and a coiled-coil domain. The TRIM5α isoform also encodes a C-terminal B30.2(SPRY) domain, differences within which define the breadth and potency of TRIM5α-mediated retroviral restriction. Because Macaca nemestrina animals are susceptible to some human immunodeficiency virus (HIV) isolates, we sought to determine if differences exist in the TRIM5 gene and transcripts of these animals. We identified a two-nucleotide deletion (Δ2) in the transcript at the 5′ terminus of exon 7 in all M. nemestrina TRIM5 cDNA clones examined. This frameshift results in a truncated protein of 300 amino acids lacking the B30.2(SPRY) domain, which we have named TRIM5θ. This deletion is likely due to a single nucleotide polymorphism that alters the 3′ splice site between intron 6 and exon 7. In some clones, a deletion of the entire 27-nucleotide exon 7 (Δexon7) resulted in the restoration of the TRIM5 open reading frame and the generation of another novel isoform, TRIM5η. There are 18 amino acid differences between M. nemestrina TRIM5η and Macaca mulatta TRIM5α, some of which are at or near locations previously shown to affect the breadth and potency of TRIM5α-mediated restriction. Infectivity assays performed on permissive CrFK cells stably transduced with TRIM5η or TRIM5θ show that these isoforms are incapable of restricting either HIV type 1 (HIV-1) or simian immunodeficiency virus infection. The expression of TRIM5 alleles incapable of restricting HIV-1 infection may contribute to the previously reported increased susceptibility of M. nemestrina to HIV-1 infection in vivo.



2000 ◽  
Vol 74 (16) ◽  
pp. 7562-7567 ◽  
Author(s):  
Baoshan Chen ◽  
Lynn M. Geletka ◽  
Donald L. Nuss

ABSTRACT Infectious cDNA clones of mild (CHV1-Euro7) and severe (CHV1-EP713) hypovirus strains responsible for virulence attenuation (hypovirulence) of the chestnut blight fungus Cryphonectria parasitica were used to construct viable chimeric viruses. Differences in virus-mediated alterations of fungal colony morphology, growth rate, and canker morphology were mapped to a region of open reading frame B extending from nucleotides 2,363 to 9,904. By swapping domains within this region, it was possible to generate chimeric hypovirus-infectedC. parasitica isolates that exhibited a spectrum of defined colony and canker morphologies. Several severe strain traits were observed to be dominant. It was also possible to uncouple the severe strain traits of small canker size and suppression of asexual sporulation. For example, fungal isolates infected with a chimera containing nucleotides 2363 through 5310 from CHV1-Euro7 in a CHV1-713 background formed small cankers that were similar in size to that caused by CHV1-EP713-infected isolates but with the capacity for producing asexual spores at levels approaching that observed for fungal isolates infected with the mild strain. These results demonstrate that hypoviruses can be engineered to fine-tune the interaction between a pathogenic fungus and its plant host. The identification of specific hypovirus domains that differentially contribute to canker morphology and sporulation levels also provides considerable utility for continuing efforts to enhance biological control potential by balancing hypovirulence and ecological fitness.



1992 ◽  
Vol 12 (8) ◽  
pp. 3315-3324 ◽  
Author(s):  
S A Veals ◽  
C Schindler ◽  
D Leonard ◽  
X Y Fu ◽  
R Aebersold ◽  
...  

Alpha interferon stimulates transcription by converting the positive transcriptional regulator ISGF3 from a latent to an active form. This receptor-mediated event occurs in the cytoplasm, with subsequent translocation of the activated factor to the nucleus. ISGF3 has two components, termed ISGF3 alpha and ISGF3 gamma. ISGF3 gamma serves as the DNA recognition subunit, while ISGF3 alpha, which appears to consist of three polypeptides, is a target for alpha interferon signaling and serves as a regulatory component whose activation is required to form ISGF3. ISGF3 gamma DNA-binding activity was identified as a 48-kDa polypeptide, and partial amino acid sequence has allowed isolation of cDNA clones. ISGF3 gamma translated in vitro from recombinant clones bound DNA with a specificity indistinguishable from that of ISGF3 gamma purified from HeLa cells. Sequencing of ISGF3 gamma cDNA clones revealed significant similarity to the interferon regulatory factor (IRF) family of DNA binding proteins in the amino-terminal 117 residues of ISGF3 gamma. The other IRF family proteins bind DNA with a specificity related to but distinct from that of ISGF3 gamma. We note sequence similarities between the related regions of IRF family proteins and the imperfect tryptophan repeats which constitute the DNA-binding domain of the c-myb oncoprotein. These sequence similarities suggest that ISGF3 gamma and IRF proteins and the c-myb oncoprotein use a common structural motif for DNA recognition. Recombinant ISGF3 gamma, like the natural protein, interacted with HeLa cell ISGF3 alpha to form the mature ISGF3 DNA-binding complex. We suggest that other IRF family members may participate in signaling pathways by interacting with as yet unidentified regulatory subunits analogous to ISGF3 alpha.



2003 ◽  
Vol 50 (1) ◽  
pp. 269-278
Author(s):  
Amr M Shabaan ◽  
Magdy M Mohamed ◽  
Mohga S Abdallah ◽  
Hayat M Ibrahim ◽  
Amr M Karim

Two Schistosoma mansoni cDNA clones 30S and 1H were identified by immunoscreening of sporocyst lambdagt11 library and by random sequencing of clones from lambdaZap libraries, respectively. Clone 30S was one of 30 clones identified by an antibody raised against tegument of 3-h schistosomules. The clone was found to encode an 81 amino-acid protein fragment. It was expressed in Escherichia coli as a fusion protein of calculated molecular mass of about 35 kDa with C-terminus of Schistosoma japonicum glutathione-S-transferase (Sj26; about 26 kDa). The recombinant fusion protein was specifically recognized by serum of rabbits immunized with irradiated cercariae. Clone 1H is one of 76 expressed sequence tags derived from an adult worm library. It encodes the complete sequence of a tegumental membrane protein, Sm13. The 104 amino-acid open reading frame encodes a protein with a calculated molecular mass of about 11.9 kDa. Clone 1H was expressed in E. coli as an insoluble fusion protein with Sj26 of about 40 kDa. In Western blots, the fusion protein was recognized by serum from rabbits vaccinated with irradiated cercariae but not by preimmune rabbit sera. The cloning, characterization and expression of those proteins are therefore potentially usefull for vaccine development.



1988 ◽  
Vol 8 (6) ◽  
pp. 2411-2418
Author(s):  
A N Roberts ◽  
V Berlin ◽  
K M Hager ◽  
C Yanofsky

The asexual developmental pathway in the life cycle of the filamentous fungus Neurospora crassa culminates in the formation of spores called conidia. Several clones of genomic Neurospora DNA have been isolated that correspond to mRNA species expressed during conidiation and not during mycelial growth (V. Berlin and C. Yanofsky, Mol. Cell. Biol. 5:849-855, 1985). In this paper we describe the characterization of one of these clones, named pCon-10a. This clone contains two genes, con-10 and con-13, which are induced coordinately during the later stages of conidiation. The two genes are separated by 1.4 kilobases of DNA; they are located on linkage group IV and are transcribed from the same strand of DNA. The molecular organization and sequence of one of these genes, con-10, and its flanking regions are presented. Full-length cDNA clones for con-10 also were isolated and sequenced, and transcription-initiation and polyadenylation sites were defined. The con-10 gene contains an open reading frame interrupted by two small introns and encodes an 86-amino-acid residue polypeptide that is both hydrophilic and weakly acidic. Expression of the con-10 gene in various mutants defective at different stages of conidiation indicates that it plays a role after aerial hyphal development. Possible functions, organization, and regulation of conidiation-specific genes are discussed.



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