An axoplasmic myosin with a calmodulin-like light chain.

Organelles in the axoplasm from the squid giant axon move along exogenous actin filaments toward their barbed ends. An approximately 235-kDa protein, the only band recognized by a pan-myosin antibody in Western blots of isolated axoplasmic organelles, has been previously proposed to be a motor for these movements. Here, we purify this approximately 235-kDa protein (p235) from axoplasm and demonstrate that it is a myosin, because it is recognized by a pan-myosin antibody and has an actin-activated Mg-ATPase activity per mg of protein 40-fold higher than that of axoplasm. By low-angle rotary shadowing, p235 differs from myosin II and it does not form bipolar filaments in low salt. The amino acid sequence of a 17-kDa protein that copurifies with p235 shows that it is a squid optic lobe calcium-binding protein, which is more similar by amino acid sequence to calmodulin (69% identity) than to the light chains of myosin II (33% identity). A polyclonal antibody to this light chain was raised by using a synthetic peptide representing the calcium binding domain least similar to calmodulin. We then cloned this light chain by reverse transcriptase-PCR and showed that this antibody recognizes the bacterially expressed protein but not brain calmodulin. In Western blots of sucrose gradient fractions, the 17-kDa protein is found in the organelle fraction, suggesting that it is a light chain of the p235 myosin that is also associated with organelles.

Contraction due to microtubule disruption is associated with increased phosphorylation of myosin regulatory light chain.

Microtubules have been proposed to function as rigid struts which oppose cellular contraction. Consistent with this hypothesis, microtubule disruption strengthens the contractile force exerted by many cell types. We have investigated alternative explanation for the mechanical effects of microtubule disruption: that microtubules modulate the mechanochemical activity of myosin by influencing phosphorylation of the myosin regulatory light chain (LC20). We measured the force produced by a population of fibroblasts within a collagen lattice attached to an isometric force transducer. Treatment of cells with nocodazole, an inhibitor of microtubule polymerization, stimulated an isometric contraction that reached its peak level within 30 min and was typically 30-45% of the force increase following maximal stimulation with 30% fetal bovine serum. The contraction following nocodazole treatment was associated with a 2- to 4-fold increase in LC20 phosphorylation. The increases in both force and LC20 phosphorylation, after addition of nocodazole, could be blocked or reversed by stabilizing the microtubules with paclitaxel (former generic name, taxol). Increasing force and LC20 phosphorylation by pretreatment with fetal bovine serum decreased the subsequent additional contraction upon microtubule disruption, a finding that appears inconsistent with a load-shifting mechanism. Our results suggest that phosphorylation of LC20 is a common mechanism for the contractions stimulated both by microtubule poisons and receptor-mediated agonists. The modulation of myosin activity by alterations in microtubule assembly may coordinate the physiological functions of these cytoskeletal components.

The ICC and its Deteriorating Relationship with Africa in Light of the Kenya Cases: What Should the EU Position be? IES Policy Brief Issue 2013/09 • November 2013

Summary. The African Union (AU), a union consisting of 54 African States, held an Extraordinary Summit on 11-12 October 2013, to discuss its relationship with the International Criminal Court (ICC or the Court). The meeting took place just weeks before the trial of Kenya’s President Uhuru Kenyatta is scheduled to begin, and was clearly intended to voice discontent and put on hold the ongoing ICC proceedings against Kenyatta as well as his deputy, Vice-President William Ruto. Before the Summit, there were even widespread rumors that the Assembly of the AU would call for a mass withdrawal of African States Parties from the ICC Statute. Eventually, the Assembly did not go that far and took two important, but less controversial decisions. It called for the granting of immunities to Heads of States from prosecutions by international criminal tribunals and requested a deferral of the ICC cases against Kenyatta and Ruto through a resolution adopted by the UN Security Council (UNSC). After providing a background to the Kenya cases, this policy brief aims to evaluate what the position of the EU and its Member States as outspoken supporters of the ICC and the fight against impunity should be, especially given the fact that France and the UK, as permanent UNSC members, could block a UNSC deferral at any time.

Filtered light. From Diag to North University Avenue, early 1930s [with woman]

On negative sleeve: 2 prints (8x10) by Sam Sturgis

An analysis of the crash experience of light trucks equipped with antilock braking systems. Technical report.

Mode of access: Internet.

Party dances for violin and piano, or reed organ, consisting of the most popular cotillions, polka quadrilles, lancers ... with the figures or steps for dancing arranged in a light and easy manner.

Mode of access: Internet.

Space-charge limit and confinement in particle acceleration with high-intensity light waves /

"AEC Contract AT(04-3)-400."

The light of the Cross in the Twentieth Century : the influence of the Church on modern civilization, her treatment of the great moral and social problems of our time, by master minds, the foundations, history and progress of her great educational institutions in the United States, her great religious orders of men and women for spreading the Gospel and teaching secular and religious knowledge, the history of the organization, development and aims of the great Catholic fraternal societies of the United States and their national federation with many other important subjects, the teachings of the Church made manifest to the modern mind /

Contents: v. 3. The glorious teachings of our holy religion