Febs Letters

doi: 10.1016/0014-5793(94)80072-3pmid: N/A

Oplatka, Avraham

doi: 10.1016/0014-5793(94)01158-3pmid: 7957949

Twenty‐five years after its proposal, the swinging theory of muscular contraction, in which the majority of scientists in the field have blindly believed, has not yet been verified. Rapidly growing experimental evidence indicates that the myosin heads do not swing. It is time to look for an alternative mechanism. Data is presented indicating that water is liberated during tension development and the extent to which it is released appears to affect the degree of tension. Since water can move (because of acquired extra energy, involvement in hydration forces etc.), it might cause protein movement.

Tanaka, Hiromitsu; Yoshimura, Yasuhide; Nishina, Yukio; Nozaki, Masami; Nojima, Hiroshi; Nishimune, Yoshitake

doi: 10.1016/0014-5793(94)01155-9pmid: 7957958

We have cloned cDNAs involved in germ cell‐specific expression. For this, a subtracted cDNA library was generated by subtracting cDNAs derived from supporting cells of mutant testis from wild‐type testis cDNAs. Detailed analyses of mRNA expression revealed that the genes corresponding to the cloned cDNAs were exclusively expressed in testes and were developmentally controlled.

Wang, Qing; Tsukahara, Satoru; Yamakawa, Hidefumi; Takai, Kazuyuki; Takaku, Hiroshi

doi: 10.1016/0014-5793(94)01139-7pmid: 7957952

The ability of homopyrimidine oligonucleotides containing 8‐oxo‐2′‐deoxyadenosine to form stable, triple helical structures with the sequence containing the recognition site for the class II‐S restriction enzyme, Ksp632‐I, was studied as a function of pH. The 8‐oxo‐2′‐deoxyadenosine‐substituted oligomers were shown to inhibit enzymatic cleavage and to bind within the physiological pH range in a pH‐independent fashion without compromising specificity.

Vila, Alejandro J.

doi: 10.1016/0014-5793(94)01141-9pmid: 7957953

The 1H NMR spectrum of Co(II) stellacyanin is reported, in which four signals not previously observed have been detected. NOE experiments were performed to assign the hyperfine shifted signals corresponding to a Cys and two His residues. Both His residues are solvent‐accessible and are shown to bind the metal ion through their Nδ1 atoms. The β‐CH2 Cys proton shifts indicate the presence of a strong axial ligand.

Suzuki, Atsushi; Shioda, Noriko; Maeda, Toshihiko; Tada, Masazumi; Ueno, Naoto

doi: 10.1016/0014-5793(94)01156-7pmid: 7957954

A variant of transforming growth factor‐β type II receptor (TGF‐βRII) cDNA was isolated from a mouse brain cDNA library. The predicted receptor is identical to previously reported mouse TGF‐βRII except that the isoform has an insertion sequence of 25 amino acids in the predicted ligand‐binding domain. By the use of reverse transcription‐polymerase chain reaction (RT‐PCR), transcripts for both isoforms were detected in all tissues and developing embryos examined. The isoform transiently expressed in COS cells showed a similar ligand‐binding specificity to authentic TGF‐βRII. These results suggest that the mouse TGF‐βRII gene generates multiple isoforms, possibly by alternative splicing, as reported for activin type IIB receptor; and an isoform which has the extra sequence in the ligand‐binding domain is also involved in the TGF‐β signal transduction.

Meßmer, Udo K.; Ankarcrona, Maria; Nicotera, Pierluigi; Brüne, Bernhard

doi: 10.1016/0014-5793(94)01161-3pmid: 7525358

Nitric oxide (NO) is a diffusible messenger involved in several patho‐physiological processes including immune‐mediated cytotoxicity and neural cell killing. NO or the products of its redox chemistry can cause DNA damage and activate subsequent lethal reactions including energy depletion and cell necrosis. However, regardless of whether it is endogenously produced in response to cytokines, or generated by chemical breakdown of donor molecules, NO can also induce apoptosis in different systems. Here, we report that NO generation in response to a cytokine induced NO‐synthase or by NO donors stimulates the expression of the tumor suppressor gene, p53, in RAW 264.7 macrophages or pancreatic RINm5F cells prior to apoptosis. NO‐synthase inhibitors such as N G‐monomethyl‐l‐arginine prevent the inducible NO generation as well as p53 expression and apoptosis. Since p53 expression is linked to apoptosis in some cells exposed to DNA damaging agents, we suggest that NO‐induced apoptosis in these cell systems is the consequence of DNA damage and subsequent expression of this tumor suppressor gene.

Detheux, Michel; Van Schaftingen, Emile

doi: 10.1016/0014-5793(94)01160-5pmid: 7957955

The cDNA presumed to encode the rat liver regulatory protein of glucokinase has been expressed in Escherichia coli and a partially soluble protein has been obtained. This recombinant protein was partially purified and found to have the same apparent molecular mass as the regulatory protein purified from rat liver. Like the latter, it inhibited rat liver glucokinase competitively with respect to glucose and its effect was sensitive to fructose 6‐phosphate and fructose 1‐phosphate.

Shimizu, Yoshifumi; Ogawa, Hiroyasu; Oka, Yoshihiro; Mizuno, Ryuzo; Sakoda, Saburo; Kishimoto, Tadamitsu; Sugiyama, Haruo

doi: 10.1016/0014-5793(94)01164-8pmid: 7957956

By subtractive hybridization using single‐stranded phagemids with directional inserts, we isolated a mouse cDNA clone, LSM‐1, from temperature‐sensitive Abelson virus‐tranformed immature B cells whose differentiation was being induced after the shift from the permissive (35°C) to the non‐permissive temperature (39°C). LSM‐1, which encodes an as yet unknown peptide of 197 amino acids, has a putative signal sequence and a trans‐membrane region, and is expressed in B‐ and T‐cell lines, in spleen, thymus, and bone marrow of adult mice, and in embryos.

Uchida, T.; Ishiguro, K.; Ohnuma, J.; Takamatsu, M.; Yonekura, S.; Imahori, K.

doi: 10.1016/0014-5793(94)01163-Xpmid: 7957957

Tau protein kinase II (TPKII) is shown by immunoprecipitation to be a complex composed of two subunits, a catalytic subunit, cdk5, and regulatory subunit, p23. By sequence analysis of p23 CDNA, p23 was found to occupy a region from the 99th amino acid residue to the C‐terminus of a novel protein with a molecular weight of 34,000 Da, suggesting that this 34 kDa protein is a precursor of p23 (pre‐p23). These findings suggest that p23 results from the processing of the precursor protein, pre‐p23. The precursor mRNA was expressed most abundantly in rat brain just before and after birth. Expression of pre‐p23, but not of cdk5, mRNA changed, coinciding with the developmental change of TPKII activity, suggesting that its expression controls the phosphorylation of tau by the TPKII/TPKI system in the neonatal brain. p23 appears to be a cdk5 activator in neuronal cells.