In the present study it was found that serotonergic apical ganglion (SAG)-forming cells in plutei of

Cell surface modification during mesenchyme ingression was examined using a monoclonal antibody (mAb), anti-Epith-1 mAb, raised against a protein

To study the effect of inserted peptides on the secretion and processing of exported proteins in Bacillus subtifis and Escherichia cofi, pBR322-derived DNA fragments coding for small peptides were inserted between the DNA coding for the 31 amino acid B. subtifis a-amylase signal peptide and that coding for the mature part of the extracellular thermostable a-amylase of B. stearothermophifus. Most of the inserted peptides (21 to 65 amino acids) decreased the production of the enzyme in B. subtifis and E. cofi, the effect of each peptide being similar in the two strains. In contrast, with one peptide (a 21 amino acid sequence encoded by the extra DNA in pTUBE638), the production of a-amylase was enhanced more than 1.7-fold in B. subtifis in comparison with that of the parent strain. The molecular masses of the thermostable a-amylases in the periplasm of the E. cofi transformants varied for each peptide insert, whereas those in the culture supernatants of the B. subtifis transformants had molecular masses similar to that of the mature enzyme. Based on the NIP,-terminal amino acid sequence of the hybrid protein from pTUBE638, it was shown that in E. cofi, the NH,-terminally extended thermostable a-amylase was translocated and remained in the periplasm after the 31 amino acid signal sequence was removed. In the case of B. subtifis, after the removal of a 34-amino acid signal sequence, the hybrid protein was secreted and processed to the mature form.