Animals ; Colonoscopy ; methods ; Colorectal Neoplasms ; pathology ; Disease Models, Animal ; Heterogeneous-Nuclear Ribonucleoproteins ; metabolism ; Precancerous Conditions ; pathology ; Rodentia

Mammalian testis exhibits remarkably high transcriptome complexity, and spermatogenesis undergoes two periods of transcriptional cessation. These make the RNA-binding proteins (RBPs) the utmost importance during male germ cell development. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a large family of RBPs implicated in many steps of RNA processing; however, their roles in spermatogenesis are largely unknown. Here, we investigated the expression pattern of 12 hnRNP family members in mouse testes and found that most detected members are highly expressed in the testis. Furthermore, we found that most of the detected hnRNP proteins (hnRNPD, hnRNPK, hnRNPQ, hnRNPU, and hnRNPUL1) display the highest signals in the nuclei of pachytene spermatocytes, round spermatids, and Sertoli cells, whereas hnRNPE1 exclusively concentrates in the manchette of elongating spermatids. The expression of these hnRNP proteins showed both similarities and specificity, suggesting their diverse roles in spermatogenesis.
Mice ; Male ; Animals ; Heterogeneous-Nuclear Ribonucleoproteins/metabolism* ; Spermatogenesis/genetics* ; Testis/metabolism* ; Spermatids/metabolism* ; Sertoli Cells ; Spermatocytes/metabolism* ; RNA-Binding Proteins/metabolism* ; Mammals

The name of SR proteins is derived from their typical RS domain that is rich in serine (Ser, S) and arginine (Arg, R). They are conserved in evolution. Up to now, 10 members of the SR protein family have been identified in humans. SR proteins contain one or two RNA binding motifs aside from the RS domain, and also possess special biochemical and immunological features. As to the functions of SR proteins, they facilitate the recruitment of the components of splicesome via protein-protein interaction to prompt the assembly of early splicesome; while in alternative splicing, tissue-specifically expressed SR protein along with the relative ratio of SR protein and heterogeneous nuclear ribonucleoprotein (hnRNP) is composed of two main regulative mechanisms to alternative splicing. Almost all of the biochemical functions are regulated by reversible phosphorylation.
Alternative Splicing ; Amino Acid Motifs ; Evolution, Molecular ; Heterogeneous-Nuclear Ribonucleoproteins ; chemistry ; Humans ; Phosphorylation ; Protein Binding ; Protein Conformation ; Protein Structure, Tertiary ; Proteomics ; methods ; RNA ; chemistry ; Spliceosomes ; chemistry ; metabolism

Enterovirus 71 (EV71) is a neurotropic pathogen that can induce hand, foot and mouth disease in children. There is an appreciable mortality rate after EV71 infections. The mechanism of action of EV71 replication is not known. Recent work has identified some of cell factors of the host that participate in the synthesis of the RNA and proteins of EV71 (e.g., hnRNP K, reticulon 3 (RTN 3)). In that work, researchers used a competitive assay to show that hnRNP K can interact with EV71 5' UTR, which is required for efficient synthesis of viral RNA. Using a yeast two-hybrid system, other researchers demonstrated that RTN 3 interacts with the N-terminal domain of EV71 2C, which is crucial for replication of viral RNA. Here, we discuss recent work focusing on the molecular mechanisms of hnRNP K and RTN 3 in the synthesis of the RNA and proteins of EV71.
Animals ; Carrier Proteins ; genetics ; metabolism ; Enterovirus A, Human ; genetics ; physiology ; Enterovirus Infections ; genetics ; metabolism ; virology ; Heterogeneous-Nuclear Ribonucleoprotein K ; Host-Pathogen Interactions ; Humans ; Membrane Proteins ; genetics ; metabolism ; Nerve Tissue Proteins ; genetics ; metabolism ; Ribonucleoproteins ; genetics ; metabolism ; Viral Proteins ; genetics ; metabolism ; Virus Replication

Protein-RNA interaction networks are essential to understand gene regulation control. Identifying binding sites of RNA-binding proteins (RBPs) by the UV-crosslinking and immunoprecipitation (CLIP) represents one of the most powerful methods to map protein-RNA interactions in vivo. However, the traditional CLIP protocol is technically challenging, which requires radioactive labeling and suffers from material loss during PAGE-membrane transfer procedures. Here we introduce a super-efficient CLIP method (GoldCLIP) that omits all gel purification steps. This nonisotopic method allows us to perform highly reproducible CLIP experiments with polypyrimidine tract-binding protein (PTB), a classical RBP in human cell lines. In principle, our method guarantees sequencing library constructions, providing the protein of interest can be successfully crosslinked to RNAs in living cells. GoldCLIP is readily applicable to diverse proteins to uncover their endogenous RNA targets.
Binding Sites ; Cell Line ; Heterogeneous-Nuclear Ribonucleoproteins ; isolation & purification ; metabolism ; Humans ; Immunoprecipitation ; methods ; Polypyrimidine Tract-Binding Protein ; isolation & purification ; metabolism ; RNA ; isolation & purification ; metabolism ; RNA-Binding Proteins ; isolation & purification ; metabolism

RNA binding proteins (RBPs) regulate the function of cells by interacting with nascent transcripts and therefore are receiving increasing attention from researchers for their roles in tissue development and homeostasis. The polypyrimidine tract binding (PTB) protein family of RBPs are important posttranscriptional regulators of gene expression. Further investigations on the post-transcriptional regulation mechanisms and isoforms of PTB proteins in the spermatogenesis show that PTB protein 1 (Ptbp1) is a predominant isoform in mitotic cells (spermatogonia), while Ptbp2 predominates in meiotic spermatocytes and postmeiotic spermatids and binds to the specific 3' untranslated region (3' UTR) of the phosphoglycerate kinase 2 (Pgk-2) mRNA, which helps to stabilize Pgk-2 mRNA in male mouse germ cells. In case of Ptbp2 inactivation in the testis, the differentiation of germ cells arrests in the stage of round spermatids, with proliferation of multinucleated cells in the seminiferous tubule, increased apoptosis of spermatocytes, atrophy of seminiferous tubules, and lack of elongating spermatids, which consequently affects male fertility. This article presents an overview on the structure of the PTB protein and its role in regulating mammalian spermatogenesis.
Animals ; Atrophy ; Gene Expression Regulation ; physiology ; Heterogeneous-Nuclear Ribonucleoproteins ; metabolism ; physiology ; Homeostasis ; Isoenzymes ; metabolism ; Male ; Mice ; Nerve Tissue Proteins ; metabolism ; physiology ; Phosphoglycerate Kinase ; metabolism ; Polypyrimidine Tract-Binding Protein ; metabolism ; physiology ; RNA, Messenger ; metabolism ; RNA-Binding Proteins ; Seminiferous Tubules ; pathology ; Spermatids ; metabolism ; Spermatocytes ; metabolism ; Spermatogenesis ; physiology ; Spermatogonia ; metabolism ; Testis ; metabolism

OBJECTIVETo identify and compare the expression profiles of differential proteins between chronic phase and blast crisis in chronic myeloid leukemia (CML) by proteomic analysis, and screen the proteins related to blast crisis.

METHODSThe total cellular proteins from the bone marrow cells at chronic phase (CP) and blast crisis (BC) in CML were separated by two-dimensional polyacrylamide gel electrophoresis (2-DE) and analyzed with ImageMaster 5.0 software to screen the differential protein spots. Differential protein spots were identified by mass spectrometry for peptide mass fingerprint in combination with database searching from SWISS-PROT. Then 3 protein spots were selected to verify at protein and mRNA levels by Western blot and semi-quantitative RT-PCR, separately.

RESULTSComparing gel pages from CML-CP and CML-BC, the expression of 13 protein spots decreased and 25 protein spots increased significantly in CML-BC. Twenty differential protein spots were identified by mass spectrometry and 15 were successfully determined. The results of Western blotting were similar to those of 2-DE and showed a high expression of hnRNPK, annexin A1 and RhoA. Semi-quantitative RT-PCR analysis showed that there was no correlation between the protein expression changes and mRNA levels of hnRNPK, annexin A1 and RhoA.

CONCLUSIONA group of proteins associated with blast crisis are obtained and the results may provide clues for further research to elucidate the role of these proteins in CML-BC carcinogenesis and to develop potential associated biomarkers.

Adult ; Aged ; Annexin A1 ; genetics ; metabolism ; Blast Crisis ; genetics ; metabolism ; Female ; Gene Expression Profiling ; Heterogeneous-Nuclear Ribonucleoprotein K ; Humans ; Leukemia, Myeloid, Chronic-Phase ; genetics ; metabolism ; pathology ; Male ; Middle Aged ; Proteomics ; methods ; RNA, Messenger ; metabolism ; Ribonucleoproteins ; genetics ; metabolism ; Young Adult ; rhoA GTP-Binding Protein ; genetics ; metabolism

OBJECTIVETo investigate the expression feature of heterogeneous nuclear ribonucleoprotein K in gastric carcinoma and its clinical significance, and to explore the relationship between hnRNPK expression and Helicobacter pylori L-form infection.

METHODSThe expression of hnRNPK protein was examined in 100 cases of gastric carcinoma, 50 paracancerous gastric tissues and 30 matched normal gastric mucosa by Elivision immunohistochemistry and hnRNPK-mRNA by in situ hybridization. Hp-L was detected with Gram staining and immunohistochemical staining.

RESULTSThe positive rates of hnRNPK protein and mRNA in gastric carcinoma were 82.0% and 86.0%, respectively, significantly higher than those in the paracancerous gastric tissues and normal controls (P < 0.05). The expression of hnRNPK protein was significantly correlated with histological differentiation, TNM stage and lymph node metastasis (P < 0.05). The positive rates of Hp-L in the three groups were 67.0%, 58.0% and 23.3%, respectively. The positive rate of Hp-L in gastric carcinoma had no significant correlation with it in the paracancerous gastric tissues, but was significantly higher than it in the normal controls (P < 0.05). In gastric carcinoma, the expression of hnRNPK protein was higher in cases of Hp-L positive patients than those of Hp-L negative cases (P < 0.05). Positive correlation existed between the expression of hnRNPK protein and Hp-L infection (r = 0.391, P < 0.01).

CONCLUSIONSThere is a higher expression of hnRNPK in gastric carcinoma. Hp-L infection may be associated with the up-regulated hnRNPK expression. The two factors may play a synergetic role in gastric carcinogenesis.

Adult ; Aged ; Aged, 80 and over ; Female ; Gastric Mucosa ; metabolism ; Helicobacter Infections ; metabolism ; microbiology ; Helicobacter pylori ; Heterogeneous-Nuclear Ribonucleoprotein K ; Humans ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Precancerous Conditions ; metabolism ; microbiology ; pathology ; RNA, Messenger ; metabolism ; Ribonucleoproteins ; genetics ; metabolism ; Stomach Neoplasms ; metabolism ; microbiology ; pathology