Regulation of reactivated elongation in lysed cell models of teleost retinal cones by cAMP and calcium.

Teleost retinal cones elongate in the dark and contract in the light. In isolated retinas of the green sunfish Lepomis cyanellus, cone myoids undergo microtubule-dependent elongation from 5 to 45 micron. We have previously shown that cone contraction can be reactivated in motile models of cones lysed with Brij-58. Reactivated contraction is both actin and ATP dependent, activated by calcium, and inhibited by cAMP. We report here that we have obtained reactivated cone elongation in lysed models prepared by the same procedures. Reactivated elongation is ATP dependent, activated by cAMP, and inhibited by calcium. The rate of reactivated elongation is proportional to the cAMP concentration between 10 microM and 0.5 mM, but is constant between 10 microM and 1.0 mM Mg-ATP. No elongation occurs if cAMP or Mg-ATP concentration is less than or equal to 5 microM. Mg-ATP is required for both cAMP-dependent and cAMP-independent processes, suggesting that Mg-ATP is required both for a regulatory process entailing cAMP-dependent phosphorylation and for a force-producing process. Free calcium concentrations greater than or equal to 10(-7) reduce the elongation rate by 78% or more, completely inhibiting elongation at 10(-5) M. This inhibition is not due to competition from calcium-activated contraction. Cytochalasin D blocks reactivated contraction, but does not abolish calcium inhibition of reactivated elongation. Thus calcium directly affects the elongation mechanism. Calcium inhibition is calmodulin dependent. The calmodulin inhibitor trifluoperazine abolishes calcium inhibition of elongation. Furthermore, calcium blocks elongation only if present during the lysis step; subsequent calcium addition has no effect. However, if calcium plus exogenous calmodulin are subsequently added, elongation is again inhibited. Thus calcium inhibition appears to require a soluble calmodulin which is lost shortly after lysis

Summing Up the Serving of Well Planned Meals

The menus given here were made for a family of average means, who have a garden or who have access to fresh vegetables and fruits. Of course, very few families could carry out this week\u27s menus in full since a menu is a very personal piece of work that must be fitted and molded to suit specific needs

A Modern Version of the Hope Box

Do you love to look at pretty dishes, linen, and silver? I do! Just to see a quaint Royal Doulton tea pot gives me a thrill and why shouldn\u27t it? It is instinctive ·for a woman to enjoy pretty table appointments. And it is often true that a woman expresses her personality more exactly in the selection of her linen, silver, and dishes than in any other of her house furnishings

What Kind of Breakfasts Do You Serve?

How is your disposition at breakfast? To start the day right, the breakfast must be right. At a successful breakfast, it is necessary to have the entire family properly dressed and ready to eat together. A bud cap and kimono are for the privacy of one\u27s room and should never be worn at breakfast. Perhaps even more to be bemoaned is the rather modern state where the lady of the house fails to arise for :breakfast and lets the man either get his own food or go down town for it. If she wishes to help spend the family income the woman should help earn that income by preparing good nourishing food and by encouraging cheerfulness to start the day right for the man of the family

Supper Without the Frying Pan

Can you get supper without using a frying pan? If you can, do you do it? Too often supper consists of cold sliced roast, hashed brown potatoes, bread, but· ter, sauce, cake, tea-this, with but slight variation, the year round. In many families, this meal represents the left overs from dinner just warmed up with no attempt to disguise their origin

Even Dinners Need Varying—365 Times a Year

It is not difficult to plan a good dinner. Secure a juicy steak or roast, one or two vegetables, a salad, and a dessert; prepare each according to your favorite method; serve simply and the feat is accomplished. To one who has mastered the art of a cheerful breakfast, and an attractive supper, the thought of company for dinner is not at all startling. Yet in the course of 365 dinners each year, one is apt to drop into a sameness of menus that is alarming

Make Thanksgiving a Real Homecoming With a Dinner in Your Church

Thanksgiving is a natural time to choose as Homecoming for the church or community center. The spirit of the Pilgrims was that of an overpowering thankfulness for the abundant harvest. They called tog.ether all the people of the village and even friendly Indians to celebrate with a banquet of venison, wild turkey, other game, vegetables, fruits, nuts, pies and puddings. Those who had much shared with the less fortunate, for they knew that the wonders of the harvest were not of man\u27s making

Thomas Sully (1783-1872): Beginning Portraitist in Norfolk

An examination of the Register of Paintings and Journal of Activities written by Thomas Sully reveals his attempt to begin a painting career in Norfolk, Virginia, 1801-1803. A discussion of portraiture in America in the early 19th century precedes the investigation of the Sully family, their theatrical background and influence on Thomas Sully. Descriptive material on Norfolk is provided as background to a close study of Sully\u27s earliest patrons Several early portraits are presented to demonstrate a progressive sophistication