No abstract available.
Mass Screening* ; src Homology Domains*

The c-Abl nonreceptor tyrosine kinase is activated in the cellular responses to genotoxic, oxidative and other forms of stress. Using tagged forms of c-Abl, the present studies demonstrate that c-Abl forms homodimers in cells. The results show that the c-Abl N-terminal regions interact with the corresponding C-terminal regions of both partners in the dimmer. Specifically, the c-Abl SH3 domain binds to a proline-rich motif at amino acids 958-982 in the c-Abl C-terminal region. Deletion of the proline-rich motif disrupts dimmer formation. These findings provide the first evidence that c-Abl forms homodimers and indicate that homodimerization can contribute to the regulation of c-Abl activity.
Humans ; Protein Multimerization ; Proto-Oncogene Proteins c-abl ; genetics ; metabolism ; src Homology Domains

In this study, the molecular mechanism of tyrosine phosphorylation of Roundabout (Robo), the transmembrane receptor for slits, was investigated. The tyrosine phosphorylation of intracellular portion of Robo was increased by the treatment of tyrosine phosphatase inhibitors in human embryonic kidney cells transfected with Robo. The Robo tyrosine phosphorylation was inhibited by the treatment of Src family kinase inhibitor, PP2. The co-transfection of constitutively active form of Fyn, not the dominant negative form of Fyn, and Robo dramatically enhanced the tyrosine phosphorylation of Robo. Furthermore, the SH2 domain of Fyn, which binds to phosphorylated tyrosine residues, interact with Robo, and the interaction was increased by the inhibition of tyrosine phosphatases. These findings indicate that the tyrosine phosphorylation of Robo is regulated by Fyn.
Humans ; Kidney ; Phosphoric Monoester Hydrolases ; Phosphorylation* ; Phosphotransferases ; src Homology Domains ; Tyrosine*

OBJECTIVE: bjective: By identifying the unknown substance responsible for binding with nebulin SH3 domain within the sarcomeric Z-line, we tried to find out Z-line structure which plays an important role on muscle contraction and maintenance of muscle funtion. METHOD: First, the bait plasmid was made by binding the DNA binding domain of Gal4 protein of yeast and the SH3 domain. Second, library plasmid was made by binding activation domain and human skeletal cDNA library. Then, the base sequence of the clone, produced by combining the two proteins expressed by transgenically converted plasmid in yeast, was analyzed. RESULT: We screened out six true positive clones and analyzed the base sequence of the two of six clones. We identified them to be alpha-actinin2. CONCLUSION: We can theorize that Neublin SH3 domain and alpha-actinin2 plays a vital role for the integration of Z-line. Thus, this is an important data in further studying muscle functions, mechanisms, and muscular disease as well.
Base Sequence ; Clone Cells ; DNA ; Gene Library ; Humans* ; Muscle Contraction ; Muscular Diseases ; Plasmids ; src Homology Domains* ; Yeasts

X-linked agammaglobulinemia (XLA) is characterized by early onset of recurrent bacterial infection, markedly reduced levels of all major classes of immunoglobulins in the serum and few mature B cells in the blood. XLA is known to be associated with mutations in Bruton's tyrosin kinase (Btk). The Btk protein consists of 5 functional domains; the pleckstrin homology (PH) domain, the Tec homology (TH) domain, the Src homology 3 (SH3) domain, the SH2 domain, and the kinase (SH1) domain. Mutations in all domains of the Btk gene have been shown to cause XLA. The large number of Alu elements within the human genome provides abundant opportunities for unequal homologous recombination events between Alu repeats, resulting in human disease. We present a case of XLA with deletion of introns 15-18 of Btk gene which were mediated by an Alu-Alu recombination event.
Agammaglobulinemia* ; Alu Elements ; B-Lymphocytes ; Bacterial Infections ; Genome, Human ; Homologous Recombination ; Humans ; Immunoglobulins ; Introns* ; Phosphotransferases ; Recombination, Genetic* ; src Homology Domains

X-linked agammaglobulinemia (XLA) is characterized by early onset of recurrent bacterial infection, markedly reduced levels of all major classes of immunoglobulins in the serum and few mature B cells in the blood. XLA is known to be associated with mutations in Bruton's tyrosin kinase (Btk). The Btk protein consists of 5 functional domains; the pleckstrin homology (PH) domain, the Tec homology (TH) domain, the Src homology 3 (SH3) domain, the SH2 domain, and the kinase (SH1) domain. Mutations in all domains of the Btk gene have been shown to cause XLA. The large number of Alu elements within the human genome provides abundant opportunities for unequal homologous recombination events between Alu repeats, resulting in human disease. We present a case of XLA with deletion of introns 15-18 of Btk gene which were mediated by an Alu-Alu recombination event.
Agammaglobulinemia* ; Alu Elements ; B-Lymphocytes ; Bacterial Infections ; Genome, Human ; Homologous Recombination ; Humans ; Immunoglobulins ; Introns* ; Phosphotransferases ; Recombination, Genetic* ; src Homology Domains

Domain database is essential for domain property research. Eliminating redundant information in database query is very important for database quality. Here we report the manual construction of a non-redundant human SH2 domain database. There are 119 human SH2 domains in 110 SH2-containing proteins. Human SH2s were aligned with ClustalX, and a homologous tree was generated. In this tree, proteins with similar known function were classified into the same group. Some proteins in the same group have been reported to have similar binding motifs experimentally. The tree might provide clues about possible functions of hypothetical proteins for further experimental verification.
Amino Acid Sequence ; Computational Biology ; Databases, Protein ; Humans ; Molecular Sequence Data ; Sequence Alignment ; src Homology Domains ; genetics

0.7). The "RUNX-1" was increased its expression in 2 hours group and "RUN and SH3 domain containing 1" was increased its expression in 4 hours group. The "CC020415", "cyclin L1", "interferon regulatory factor1", "early growth response 1", "immediate early response 2", and "immediate early response 3" genes were increased their expression in 2 and 4 hours after FISS application. In conclusion, we could find many genes that were probably related to the FISS application. Interestingly, most of them were placed in similar molecular pathways and these findings improve the reliability of chip data and usefulness in overall screening. From this experiment, we could find many items for further study and it will make improvement in the understanding of intracellular events in response to FISS.]]>
DNA, Complementary ; Fibroblasts ; Gene Expression ; Homeostasis ; Humans ; Mass Screening ; Mouth ; Mouth Mucosa ; Oligonucleotide Array Sequence Analysis ; RNA ; src Homology Domains

OBJECTIVE: Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediate the hyperpolarizationactivated currents (Ih) that participate in regulating neuronal membrane potential and contribute critically to pacemaker activity, promoting synchronization of neuronal networks. However, distinct regional and cellular localization of HCN channels in the brain have not been precisely defined. Aim of this study was to verify the precise cellular location of HCN1 channels in rat cerebellum to better understand the physiological role these channels play in synaptic transmission between CNS neurons. METHODS: HCN1 expression in rat brain was analyzed using immunohistochemistry and electron-microscopic observations. Postsynaptic density-95 (PSD-95), otherwise known as locating and clustering protein, was also examined to clarify its role in the subcellular location of HCN1 channels. In addition, to presume the binding of HCN1 channels with PSD-95, putative binding motifs in these channels were investigated using softwaresearching method. RESULTS: HCN1 channels were locally distributed at the presynaptic terminal of basket cell and exactly corresponded with the location of PSD-95. Moreover, nine putative SH3 domain of PSD-95 binding motifs were discovered in HCN1 channels from motif analysis. CONCLUSION: Distinct localization of HCN1 channels in rat cerebellum is possible, especially when analyzed in conjunction with the SH3 domain of PSD-95. Considering that HCN1 channels contribute to spontaneous rhythmic action potentials, it is suggested that HCN1 channels located at the presynaptic terminal of neurons may play an important role in synaptic plasticity.
Action Potentials ; Animals ; Brain ; Cerebellar Cortex* ; Cerebellum ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; Immunohistochemistry ; Membrane Potentials ; Neurons ; Plastics ; Presynaptic Terminals ; Rats* ; src Homology Domains ; Synaptic Transmission

BACKGROUNDLaryngeal carcinoma is a common malignant tumor of the upper respiratory tract, and in 95% of cases the tumor is laryngeal squamous cell carcinoma (LSCC). The abnormity of SH3-domain GRB2-like 2 (SH3GL2) gene was found in LSCC. In order to clarify the relationship between SH3GL2 gene and LSCC, we evaluated the expression of the SH3GL2 gene in LSCC.

METHODReal-time PCR, immunohistochemistry and Western blotting were used to detect the mRNA and protein expression and find the various rules of SH3GL2 gene in LSCC.

RESULTSThe result of real-time PCR showed that the expression level of SH3GL2 mRNA in LSCC tissue was apparently down-regulated; immunohistochemical analysis showed that SH3GL2 protein was mainly located in cytoplasm, the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathological classification of LSCC; the result of Western blotting showed that SH3GL2 protein was down-regulated significantly in LSCC samples, especially in metastatic lymph nodes.

CONCLUSIONSThese results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with the pathological classification which indicate that SH3GL2 participates in the development and progression of LSCC. And it may be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion and metastasis of laryngeal carcinoma.

Adaptor Proteins, Signal Transducing ; analysis ; genetics ; Blotting, Western ; Carcinoma, Squamous Cell ; chemistry ; genetics ; Humans ; Immunohistochemistry ; Laryngeal Neoplasms ; chemistry ; genetics ; Polymerase Chain Reaction ; src Homology Domains