PubMed Health⌕ Search

Biomedical subjects

A Shanavas

Publications and source records attributed to A Shanavas.

6 recordsLinked to original sources
PubMed2002

Juvenile hormone stimulated tyrosine kinase-mediated protein phosphorylation in the CNS of the silk worm, Bombyx mori.

In vitro studies with the larval CNS of the silkworm, Bombyx mori revealed the phosphorylation of a 48-kDa protein, which was not dependent on cyclic nucleotides. Studies also revealed modest phosphorylation of this protein by a calcium-dependent but calmodulin-independent mechanism. However, phosphorylation of this protein was greatly enhanced in the presence of juvenile hormone (JH) I by a calcium-independent mechanism. This stimulatory effect of JH was seen in both homogenates as well as in intact CNS of Bombyx. Immunoblotting studies revealed the cross-reaction of this 48-kDa protein with phosphotyrosine monoclonal antibody and the phosphorylation of this protein was inhibited by genistein. This study suggests that the 48-kDa protein is a substrate for tyrosine kinase. The phosphorylation of this protein was also observed in other larval tissues such as salivary gland, fat body, and epidermis of Bombyx.

Animals↗
PubMed2000

tau kinases in the rat heat shock model: possible implications for Alzheimer disease.

We have previously shown, by using the phosphate-dependent anti-tau antibodies Tau-1 and PHF-1, that heat shock induces rapid dephosphorylation of tau followed by hyperphosphorylation in female rats. In this study, we analyzed in forebrain homogenates from female Sprague-Dawley rats the activities of extracellular signal regulated kinase 1/2 (ERK1/2), c-Jun NH(2)-terminal kinase (JNK), glycogen synthase kinase-3beta (GSK-3beta), cyclin-dependent kinase 5 (Cdk5), cAMP-dependent protein kinase A (PKA), and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) at 0 (n = 5), 3 (n = 4), 6 (n = 5), and 12 (n = 5) h after heat shock and in non-heat-shocked controls (n = 5). Immunoprecipitation kinase assays at 0 h showed suppression of the activities of all kinases except of GSK-3beta, which showed increased activity. At 3-6 h, the activities of ERK1/2, JNK, Cdk5, and GSK-3beta toward selective substrates were increased; however, only JNK, Cdk5, and GSK-3beta but not ERK1/2 were overactivated toward purified bovine tau. At 3-6 h, kinase assays specific for PKA and CaMKII showed no increased activity toward either tau or selective substrates. All of eight anti-tau antibodies tested showed dephosphorylation at 0 h and hyperphosphorylation at 3-6 h, except for 12E8, which showed hyperphosphorylation also at 0 h. Immunoblot analysis using activity-dependent antibodies against ERK1/2, JNK, and GSK-3beta confirmed the above data. Increased activation and inhibition of kinases after heat shock were statistically significant in comparison with controls. Because tau is hyperphosphorylated in Alzheimer disease these findings suggest that JNK, GSK-3beta, and Cdk5 may play a role in its pathogenesis.

Alzheimer Disease↗
PubMed1998

Identification, characterization, immunocytochemical localization, and developmental changes in the activity of calcium/calmodulin-dependent protein kinase II in the CNS of Bombyx mori during postembryonic development.

In the present investigation, in vitro phosphorylation of CNS proteins of the silkworm Bombyx mori during the postembryonic development have been studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of phosphorylated proteins revealed the presence of major phosphoproteins of 59/60 kDa. Based on molecular mass, calcium/calmodulin-dependent autophosphorylation, substrate specificity, KN-62 inhibition, apparent Km for ATP and syntide-2, these proteins were identified as calcium/calmodulin-dependent protein kinase II (CaM kinase II). Anti-rat CaM kinase II monoclonal antibody showed immunoreactivity with Bombyx CaM kinase II isoforms. This kinase showed a high degree of autophosphorylation in neural tissue. During postembryonic development of Bombyx, two distinct peaks of enzyme activity could be noticed, one at the late-larval and another at the late-pupal stage, which were associated with an increase in amount of the enzyme. These results suggested that the expression of CaM kinase II in the CNS of Bombyx was developmentally regulated.

Aging↗
PubMed1996

Ecdysteroid mediated muscle actin synthesis during the larval development of rice moth, Corcyra cephalonica.

Protein fractions from the whole body homogenates were separated on SDS-PAGE and the muscle actin band was identified by western blotting, using commercial antibody raised against chick back muscle actin (Sigma Chemical Co., USA). The antibody was found to be specific for muscle actin, as it did not cross react with cytoplasmic actin of the nervous system. The molecular weight of the muscle actin in Corcyra was found to be around 46 kDa. The concentration of actin was found to be more or less the same in penultimate and early-last instar larvae and it increased during mid and late-last instar development. Thereafter, it has dropped to its minimum during the pupal stage. But, once again it increased to its maximum in adults. Thorax-ligation in early and late-last instar larvae resulted in decreased synthesis of muscle actin and this was more pronounced after 48 h of ligation. Injection of 20-hydroxyecdysone to insects which were thorax-ligated for 24 and 48 h was found to significantly increase the concentration of actin, suggesting that the ecdysteroids mediate the muscle actin synthesis during the larval development of Corcyra.

Actins↗
PubMedDate not supplied

Non-Hodgkin's lymphoma in children: disease pattern and survival.

The use of intensive chemotherapy and incorporation of prophylactic treatment of the central nervous system have dramatically improved the outcome of children with non-Hodgkin's lymphoma (NHL). The authors analyzed retrospectively the disease characteristics and survival data of 34 children with NHL during a 7-year period. There were 26 boys and 8 girls with a median age of 8 years. The primary sites were the abdomen (41%) and peripheral node (41%). Histopathologically lymphoblastic and undifferentiated lymphoma (small nonclaved cell lymphoma) were equally distributed (41%). Thirteen patients had localized disease (stage I and II) and 21 patients had advanced disease (stage III and IV). Surgical removal of the primary tumor was done in 6 patients with localized gastrointestinal lesions. All 34 patients received chemotherapy, either cyclophosphamide, vincristine, methotrexate, and prednisolone (COMP) or adriamycin, cyclophosphamide, vincristine, and prednisolone (ACOP). Thirty patients achieved complete remission (88.2%). The 5-year event-free survival rate was 64%. The results indicate that most children with localized disease can be cured by COMP chemotherapy, but more aggressive chemotherapy is necessary to improve survival in advanced-stage disease.

Adolescent↗