Protein H--a surface protein of Streptococcus pyogenes with separate binding sites for IgG and albumin

Protein H, a molecule expressed at the surface of some strains of Streptococcus pyogenes, has affinity for the constant (IgGFc) region of immunoglobulin (Ig) G. In absorption experiments with human plasma, protein H-sepharose could absorb not only IgG but also albumin from plasma. The affinity constant for the reaction between albumin and protein H was 7.8 x 10(9) M-1, which is higher than the affinity between IgG and protein H (Ka = 1.6 x 10(9) M-1). Fragments of protein H were generated with deletion plasmids and polymerase chain reaction (PCR) technology. Using these fragments in various protein-protein interaction assays, the binding of albumin was mapped to three repeats (C1-C3) in the C-terminal half of protein H. On the albumin molecule, the binding site for protein H was found to overlap the site for protein G, another albumin- and IgGFc-binding bacterial surface protein. Also IgGFc-binding could be mapped with the protein H fragments and the region was found N-terminally of the C repeats. A synthetic peptide (25 amino acid residues long) based on a sequence in this region was shown to inhibit the binding of protein H to immobilized IgG or IgGFc. This sequence was not found in previously described IgGFc-binding proteins. However, two other cell surface proteins of S. pyogenes exhibited highly homologous regions. The results identify IgGFc- and albumin-binding regions of protein H and further define and emphasize the convergent evolution among bacterial surface proteins interacting with human plasma proteins.

Different interactions of Grb2/Ash molecule with the NGF and EGF receptors in rat pheochromocytoma PC12 cells

We have previously shown that nerve growth factor (NGF) induces a rapid and relatively continuous activation of Ras in rat pheochromocytoma PC12 cells while epidermal growth factor (EGF) activates Ras transiently, and that tyrosine kinase activity of the NGF receptor is essential for the activation of Ras (Muroya et al., Oncogene, 7, 277-281, 1992). In order to explore the signaling mechanism from tyrosine kinase to Ras activation in more detail, interactions between two adaptor molecules, Shc and Grb2/Ash, which contain Src homology regions, and their interactions with the NGF and EGF receptors were examined. Both NGF and EGF induced rapid tyrosine phosphorylation of Shc and its association with both the receptors and with Grb2/Ash. When cells were stimulated with EGF at 4 degrees C, the activation of Ras proceeded slowly and MAP kinase activation was quite low. Under such restricted conditions, tyrosine-phosphorylated Shc formed a complex with Grb2/Ash, suggesting that the complex formation may be one of the immediate early responses. In contrast to Shc, Grb2/Ash bound to EGF receptor but did not form a stable complex with the NGF receptor. These results suggest that there may be an alternative pathway for the activation of Ras in PC12 cells.

Long-term follow-up of patients with epithelial carcinoma of the ovary

OBJECTIVES

To determine the long-term outcomes of patients with epithelial ovarian cancer.

METHODS

A group of 298 patients with epithelial ovarian cancer were treated with combination chemotherapy between July 1979 and January 1986 at the Tokai Ovarian Tumor Study Group. Long-term results of these patients were analyzed.

RESULTS

Five-year survival and 10-year survival rates of all the patients were 53% and 47%, respectively. Five-year survival and 10-year survival rates for stage I were 89% and 79%, 59% and 56% for stage II, 27% and 22% for stage III, and 9% and 9% for stage IV, respectively. Survival of mucinous and endometrioid cell types were decreased after 5 or more years. In stages II-IV, cisplatin-based chemotherapy produced better results than mitomycin-C, 5-Fu, cytarabine (MFC) therapy.

CONCLUSIONS

Long-term results of epithelial ovarian cancer were not favorable even in mucinous and endometrioid cell types. For long-term results, cisplatin-based chemotherapy was effective in advanced ovarian cancer. Long-term follow-up of ovarian cancer is important and necessary.

Site-directed mutagenesis, fluorescence, and two-dimensional NMR studies on microenvironments of effector region aromatic residues of human c-Ha-Ras protein

The Tyr residues in positions 32 and 40 of human c-Ha-Ras protein were replaced by site-directed mutagenesis (Y32F, Y32W, Y40K, and Y40W) to examine their roles in the signal-transducing activity and the sensitivity to the GTPase activating protein (GAP). The signal-transducing activity of the oncogenic Ras protein in PC12 cells was lost upon mutations Y32F and Y40K, but retained upon mutations Y32W and Y40W. These results suggest that residues 32 and 40 are both required to have aromatic groups and residue 32 is further required to have a hydrogen donor. On the other hand, three mutations (Y32F, Y32W, and Y40W) caused no appreciable reduction in either GAP-binding affinity or GAP sensitivity. By the Y40K mutation, GAP-binding affinity was slightly lowered, while GAP sensitivity was drastically impaired. Therefore, for residues 32 and 40 of Ras, interactions with GAP appear to be different from those with the target of signal transduction in the PC12 cell. As for the Y32W-Ras protein bound with an unhydrolyzable GTP analogue (GMPPNP), the Trp32 fluorescence is appreciably red-shifted, weaker, and more susceptible to KI quenching as compared to that of the GDP-bound form. Two-dimensional NMR spectroscopy with selectively deuterated Ras proteins revealed fewer and weaker nuclear Overhauser effects on the aromatic protons of Trp32 in the GMPPNP-bound form than in the GDP-bound form. This indicates that the side chain of Trp32 is more exposed to the solvent in the GMPPNP-bound form than in the GDP-bound form.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidermal growth factor-receptor mutant lacking the autophosphorylation sites induces phosphorylation of Shc protein and Shc-Grb2/ASH association and retains mitogenic activity

Epidermal growth factor (EGF) receptor (EGFR) can induce cell growth and transformation in a ligand-dependent manner. To examine whether the autophosphorylation of EGFR correlates with the capacity of the activated EGFR to induce cell growth and transformation, we truncated the human EGFR just after residue 1011, removing all three major autophosphorylation sites (DEL1011). Further, a point mutation was introduced at another autophosphorylation site, Tyr-992-->Phe (DEL1011+F992). The wild-type and mutant receptors were stably expressed in a NIH 3T3 variant cell line that expresses an extremely low level of endogenous EGFR and does not grow with EGF. As expected, DEL1011 and DEL1011+F992 were found to be severely impaired in EGF-induced autophosphorylation, due to the deletion of the appropriate target tyrosines. However, mutant receptors still could induce EGF-dependent DNA synthesis, morphological transformation, and anchorage-independent growth, although the extent of these was significantly reduced when compared with wild-type EGFR. EGF-induced tyrosine phosphorylation of Ras-GTPase activating protein-associated protein p62 and phospholipase C gamma 1 was dramatically reduced in the cells expressing DEL1011 and DEL1011+F992. On the other hand, tyrosine phosphorylation of Shc, complex formation of Shc-Grb2/Ash, and activation of microtubule-associated protein kinase were still fully induced upon EGF stimulation without binding of Shc or Grb2/Ash to the mutant receptor. Thus, tyrosine phosphorylation of Shc may play a crucial role for activating Ras and generating mitotic signals by the activated EGFR mutant.

Recurrence of epithelial ovarian carcinoma after clinical remission

One hundred and eighty-eight patients with epithelial ovarian carcinoma were treated with primary cytoreductive surgery and subsequent combination chemotherapy. The first recurrent findings such as sites and disease-free interval were analyzed in 141 patients who were clinically remitted 6 months after operation or chemotherapy. Fifty-seven cases had a recurrence. Five-year disease-free survival rates were 75, 72, 29, and 0% in stage I, II, III, and IV, respectively. Twenty-one of 22 patients with > 2 cm maximum residual tumor died, although they once achieved clinical remission. Significant differences were observed between histologic types, and the disease-free survival rate was lowest for serous cystadenocarcinoma. Nine of 15 stage IV patients with serous histology experienced remission, but none of the 8 in stage IV with other histologies did so, suggesting that serous adenocarcinoma is sensitive to chemotherapy and conducive to clinical remission. However, all stage IV patients in remission encountered a recurrence. Intra-abdominal cavity and lymph node were frequently the initial recurrent sites (38 and 27%, respectively). On the other hand, the incidence of distant recurrence was as high as 27%, and 8 of 16 cases with distant recurrence were stage I. Survival time after recurrence was not different among initial sites of recurrence and mean survival time was 15 months.

Striatal dopamine turnover during treadmill running in the rat: relation to the speed of running

To evaluate the physiological action of striatal dopamine (DA) in exercise, rats were trained to run on a straight treadmill. Extracellular DA and its metabolites, dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) were measured by in vivo microdialysis, and striatal tissue tyrosine hydroxylase (TH) activity and monoamine oxidase (MAO) activity were measured using high performance liquid chromatography (HPLC) and spectrophotometer. DA turnover was increased by running, and the increase in DOPAC and HVA was closely related to the speed of running, while the increase in DA had no relationship to the speed. The threshold for the increase in DA, DOPAC, and HVA was between 300 and 660 cm/min. Striatal tissue TH activity was elevated up to 135% of basal values after the rats were trained for 7 days to run at 1800 cm/min. Just after running for 20 min, there was a further increase to 180%. These values became 150% and 90% of basal values at 2 h and 6 h, showing a similar time course as DA detected by microdialysis. MAO-B activity increased up to 160% of basal values after 7 days training but decreased to 130% and 110% just after and 2 h after running, then increased to 145% 6 h after running. MAO-A showed a similar variation as MAO-B. These data suggest that both the synthesis and metabolism of DA have a close relationship with physical exercise and might contribute to adjusting extracellular DA levels within an adequate range in response to exercise intensity.

Identification of a single base insertion in the COL4A5 gene in Alport syndrome

We identified a novel mutation in the COL4A5 gene of a Japanese patient with Alport syndrome. A combination of in vitro amplification of the exons with single strand conformation polymorphisms (SSCP) analysis suggested the presence of a mutation in exon 48. Sequencing of the amplified DNA revealed a single base (T) insertion which was between nucleotides T 4750 and G 4751 within the methionine 1516. This mutation caused a shift in the reading frame of nine amino acids and introduced a premature termination signal that would be expected to lack about two-thirds of the noncollagenous (NC1) domain. This mutation may interfere with type IV collagen assembly leading to increased permeability and play a causative role in the glomerular basement membrane abnormality of this patient with typical Alport syndrome. Gene tracking by restriction enzyme NlaIII digestion revealed that the patient's mother is heterozygous whereas the patient's brother and one sister are normal, albeit they have hematuria and proteinuria. Without gene analysis, they would have been misdiagnosed. We propose that the diagnosis of Alport syndrome should be made on the basis of both clinical phenotypes and molecular defects.

Follow up study on children with dyslipidaemia detected by mass screening at 18 months of age: effect of 12 months dietary treatment

The present study was done to evaluate the effect of short-term dietary therapy on 148 dyslipidaemic children (24 familial hypercholesterolaemia, 105 non-familial hypercholesterolaemia and 19 hypertriglyceridaemia), detected by mass screening in children at 18 months of age. In the model diet used for treatment, 15% of the total calories were obtained from protein, 27% from fat and 57% from carbohydrate. Cholesterol intake was set at < 200 mg/day and the ratio of polyunsaturated to saturated fatty acid (P/S ratio) was 1.2. When compared to the composition of the diet ingested by the dyslipidaemic children, only the P/S ratio changed from 0.7 to 1.2. During 12 months treatment, levels of total cholesterol, low density lipoproteins cholesterol and apoB decreased by 10%-15% in children with familial and non-familial hypercholesterolaemia. There was no significant change in the levels of high density lipoproteins. In 19 children with hypertriglyceridaemia, the intake of carbohydrate was limited to 55% of the total calories consumed and after 12 months of treatment, triglyceride levels reverted to normal. Throughout the study period, approximately 70% of the children on this dietary therapy were seen in our clinics every 3-6 months and physical development was within normal ranges. These results, taken together, indicate that dietary therapy can be effective for correcting dyslipidaemia, even in young children.

Purification of a novel ras GTPase-activating protein from rat brain

GTPase-activating protein (GAP) and neurofibromin, a gene product of neurofibromatosis type I gene, have been identified as factors that stimulate GTPase activity of ras p21. We have previously suggested the presence of novel GAP activity that is immunologically distinguishable from GAP or neurofibromin in both the cytosolic and the particulate fractions of rat brain (Hattori, S., Maekawa, M., and Nakamura, S. (1992) Oncogene 7, 481-485). We have purified this novel GAP molecule from the cytosolic fraction of rat brain by more than 200,000-fold by five successive column chromatographies with a recovery of 6%. Apparent molecular mass of this molecule was estimated to be 100 kDa (p100GAPras). The same p100GAPras was purified from the particulate fraction after extraction with high salt. The activation of GTPase was observed with normal ras p21 but not with oncogenic ras p21, Rap1B/smg21B, or Ram25K. The dissociation constant of p100GAPras toward ras p21 estimated by competitive inhibition using ras p21 in complex with nonhydrolyzable analog of GTP was two times higher than that of neurofibromin and was lower than that of GAP by 2 orders of magnitude. These results clearly indicate that p100GAPras is a novel ras GAP molecule.

Differential contribution of M(r) 120 kDa rasGTPase-activating protein and neurofibromatosis type 1 gene product during the transition from growth phase to arrested state in human fibroblasts accompanied by a unique rasGTPase-activating activity

Using octyl glucoside-solubilized cell extracts from human fibroblasts during growth phase to G0/G1 arrest state, we found that while the number of M(r) 120 kDa rasGTPase-activating protein (p120GAP) molecules per cell decreases to half its original levels, the amount of neurofibromatosis type 1 gene product (NF1, a neurofibromin) remains constant during the transition. The contribution of p120GAP to the total rasGTPase-activating (rasGA) activity in growing cells was found to be larger than that observed in arrested cells (84% vs 53%). On the other hand, NF1 contributes less than 15% of the total rasGA activity in either extract. These results indicate that the qualitative changes occur in the contributors to rasGA activity during transition. They also suggest that a unique rasGA activity exists in the arrested cells, which was obtained separately from both p120GAP and NF1 by heparin-Sepharose column chromatography.

Idiopathic sclerosing peritonitis in a man

Idiopathic sclerosing peritonitis (ISP) is a rare condition which has been mainly reported in young adolescent women as a cause of small bowel obstruction. In these patients the small bowel is sometimes encased in a fibrous sac called an "abdominal cocoon". We describe a 62-year-old man who underwent exploratory laparotomy for ascites and abdominal mass. Laparotomy showed 5.4 l of ascites and the entire small bowel was encased in a fibrous sausage-like cocoon. The pathological findings were characteristic of sclerosing peritonitis.

Both the SH2 and SH3 domains of human CRK protein are required for neuronal differentiation of PC12 cells

Human CRK protein is a homolog of the chicken v-crk oncogene product and consists mostly of src homology region 2 (SH2) and SH3, which are shared by many proteins, in particular those involved in signal transduction. SH2 has been shown to bind specifically to phosphotyrosine-containing peptides. We report here that both SH2 and SH3 are required for signaling from CRK protein. Microinjection of the CRK protein induced neurite formation of rat pheochromocytoma cell line PC12. This activity was abolished by mutation of the CRK protein in either SH2 or SH3. The neuronal differentiation induced by the CRK protein was blocked by an excess amount of peptides containing CRK SH3. Moreover, we identified three proteins, of 118, 125, and 136 kDa, which bound specifically to CRK SH3. The CRK-induced neuronal differentiation was also suppressed by monoclonal antibodies against either CRK SH2 or p21ras. These results suggest that both SH2 and SH3 of the CRK protein mediate specific protein-protein binding and that the resulting multimolecular complex generates a signal for neurite differentiation through activation of p21ras.

Purification and molecular cloning of a novel acidic calmodulin binding protein from rat brain

An acidic protein was identified among the insoluble proteins of a growth cone-enriched fraction, and this protein was purified from the Triton- and high NaCl-insoluble fraction of newborn rat brain using several column chromatographies after solubilization at an alkaline condition. The purified protein showed a Ca(2+)-dependent calmodulin binding activity. This protein showed an anomalous behavior in SDS-polyacrylamide gel electrophoresis as that observed in case of GAP-43 (neuromodulin, F1, pp46, p57, B-50) and MARCKS (p87, p80), namely shifts of apparent molecular weights under different acrylamide concentrations. Its physicochemical characteristics, such as heat stability, acidic isoelectric point, and solubility in a 2.5% perchloric acid solution, also resemble the properties of these proteins. cDNA cloning of this protein showed that the NH2-terminal 50-amino acid sequence was almost identical to CAP-23, a previously reported chicken protein of unknown function. Since the COOH-terminal half-regions of these proteins are less similar, the entire sequences of these proteins have 65% homology (52% identity), suggesting that these proteins belong to a family. Immunoblotting of several tissue extracts using a monoclonal antibody against this protein showed its specific expression in brain.

Monoclonal antibodies to human polymorphonuclear leukocyte gelatinase (type IV collagenase) are cross-reactive with fibroblast gelatinase

Four monoclonal antibodies to human polymorphonuclear leukocyte gelatinase, 100 kDa type IV collagenase, 1G5, 4C6, 4G6 and 4H4 clones, were generated by immunizing Balb/c mice and fusing the mouse spleen cells with P3U1 cells. By using the enzyme-linked immunosorbent assay method, two clones, 4G6 and 1G5, were found to cross-react with human fibroblast 75kDa gelatinase, although none of the four antibodies inhibited gelatinase activity. Selective detection of 75 kDa and 100 kDa gelatinases produced by human skin fibroblasts and fibrosarcoma cells (HT 1080) in culture was successfully demonstrated by immunostaining with combined uses of 4H4 and 4G6 clones.

[Double meningoencephalitis with herpes simplex virus and rubella virus]

A 47-year-old man suffered from a headache, fever and memory disturbance. He was admitted to Morimoto Hospital. Neurological examination revealed disturbance of memory of recent events. Cranial nerves were normal. Muscle strength of the extremities was normal, except for Barré's sign of the right upper extremity. Deep tendon reflexes were exaggerated bilaterally, and extensor plantar response of the left side was elicited. Sensory examination showed no abnormality. Cerebellar sign was not recognized. Meningeal sign was slightly but clearly showed. CT scan demonstrated brain swelling at the right insular cortex region followed by severe hydrocephalus with dilatation of the lateral and the third ventricles. Cerebrospinal fluid showed high CSF pressure (250 mmH2O), pleocytosis (C.C. 359/mm3) and elevated protein level (213 mg/dl). Virological examination revealed herpes simplex virus (HSV) (CF) 32x, HSV-1 IgG (EIA) 4,050X, rubella virus IgE (EIA) 6,060X, cytomegalovirus (CMV) IgG (EIA) 1,130X in serum and HSV (CF) 1X, HSV-1 IGg (EIA) 1,430X, rubella virus IgG (EIA) 1,480X, CMV IgG (EIA) 587X in CSF. The ratio of serum/CSF of HSV and rubella virus titers by EIA methods were 2.83 and 4.10, respectively. He was treated by acyclovir 1,000 mg/day and gamma globulin, but his condition get worse acutely and died at 15th hospital days. This case was considered as a meningoencephalitis caused by simultaneous HSV and rubella virus infection.

Insulin stimulates association of insulin receptor substrate-1 with the protein abundant Src homology/growth factor receptor-bound protein 2

Insulin activates the ras proto-oncogene product p21ras (Ras) by stimulating conversion of the inactive GDP-bound form of Ras to the active GTP-bound form. The protein ASH (for abundant Src homology) (Matuoka, K., Shibata, M., Yamakawa, A., and Takenawa, T. (1992) Proc. Natl. Acad. Sci. U. S. A. 89, 9015-9019) is composed of one Src homology (SH)2 and two SH3 domains and highly homologous to the Caenorhabditis elegans protein sem-5 that couples a tyrosine kinase to a Ras protein. We have studied an interaction of ASH with insulin-stimulated tyrosine-phosphorylated proteins in Chinese hamster ovary cells overexpressing human insulin receptors (CHO-HIR cells). In an anti-ASH (alpha ASH) immunoprecipitates, we detected a 170-kDa phosphoprotein that was recognized by an anti-phosphotyrosine antibody and an anti-insulin receptor substrate 1 antibody (alpha IRS-1) from the insulin-stimulated [32P]orthophosphate-labeled CHO-HIR cells. We failed to detect the tyrosine phosphorylation of the protein ASH. These data suggested that insulin stimulates IRS-1.ASH complex formation in intact cells. Incubation of an ASH fusion protein with the lysates of insulin-stimulated CHO-HIR cells revealed that the fusion protein of ASH was able to bind the tyrosine-phosphorylated 170-kDa protein that was recognized by alpha IRS-1. We also demonstrated that fusion protein of ASH was able to bind the fusion protein of tyrosine-phosphorylated IRS-1 fragments, suggesting that ASH is able to bind tyrosine-phosphorylated IRS-1 directly. These data suggest that IRS-1.ASH complex formation may play a role in coupling the insulin receptor kinase to a Ras signaling pathway. Furthermore, we observed an insulin-stimulated phosphatidylinositol (PI) 3-kinase activity in alpha ASH immunoprecipitates, suggesting the formation of an ASH.IRS-1.PI 3-kinase complex. This complex formation was detected as early as 10 s after insulin stimulation in intact CHO-HIR cells. This is the first report that supports the notion that IRS-1 binds several signal transducing molecules containing SH2 domains, thus serves as an SH2 docking protein that transduces insulin's signal multidirectionally.