ABSTRACT
It has been shown that tropomodulin 1 is phosphorylated at serine and threonine residues by TRPM7 kinase. The phosphorylation sites for TRPM7 kinase in the N-terminal functional domain of tropomodulin 1 have been identified, which include tropomyosin-binding and actin-capping regions. It has been found that the phosphorylation-mimicking mutation T54E resulted in the loss of the capping ability of the N-terminal tropomodulin domain; however, its tropomyosin-binding ability did not change. We further hypothesize that the phosphorylation of tropomodulin by TRPM7 kinase may play a role in the regulation of the dynamics of actin filaments.
Subject(s)
Protein Kinases/chemistry , Transient Receptor Potential Channels/chemistry , Tropomodulin/chemistry , Actins/chemistry , Amino Acid Sequence , Molecular Sequence Data , Mutation , Phosphorylation , Protein Isoforms/chemistry , Protein Kinases/genetics , Transient Receptor Potential Channels/geneticsABSTRACT
The protein compositions of archaebacteria (Halobacterium salinarium, Halobacterium volcanii, Halobacterium saccharovorum and Natronobacterium pharaonis 12) flagella have been studied. It was found that flagella of these archaebacterial species are made up of flagellins. The flagellins of H. salinarium, H. volcanii and H. saccharovorum are glycosylated. Based on the known primary sequences of Halobacterium halobium R1M1 flagellin genes, oligonucleotides to the 5'- and 3'-ends of locus A containing two out of five such genes have been synthesized. The amplified by primers fragment of chromosomal DNA coding for H. halobium flagellins A1 and A2 was used as a probe for detecting homologous sites in archaebacterial DNA. Southern blotting hybridization revealed that the DNA of all archaebacterial species tested in this study contains sequences that are homologous to genes flg A1 and flg A2 of H. halobium.
