Dictyostelium discoideum contains a gene encoding a myosin I heavy chain.

Abstract

We have cloned and completely sequenced a gene encoding the heavy chain of Dictyostelium myosin I. Like the myosin I molecules from Acanthamoeba, the Dictyostelium myosin I heavy chain is composed of a globular head domain fused to a 45-kDa glycine-, proline-, and alanine-rich carboxyl-terminal domain, rather than the coiled-coil rod domain of conventional myosins. Comparisons of the Dictyostelium myosin I heavy-chain amino acid sequence with those of the Acanthamoeba myosins I reveal that they are highly similar throughout, including the unconventional carboxyl-terminal domains. The Dictyostelium myosin I gene is expressed in growing cells as a 3600-nucleotide mRNA. Measurements of the steady-state level of this mRNA at different times during starvation-induced aggregation and development are consistent with a role for myosin I in chemotaxis and aggregation. Generation of Dictyostelium cells lacking myosin I by gene disruption and/or antisense RNA production should provide a way to test directly the role of this nonfilamentous myosin in cell motility. These experiments will be simplified by the fact that Southern blot analyses of Dictyostelium genomic DNA are consistent with there being a single myosin I heavy-chain gene.

• Authors: G Jung, C L Saxe 3rd, A R Kimmel, J A Hammer 3rd
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 86 Issue 16 Pg. 6186-90 (Aug 1989) ISSN: 0027-8424 [Print] United States
• PMID: 2762320 (Publication Type: Journal Article)

Chemical References

• DNA, Fungal
• Myosin Subfragments
• Peptide Fragments
• Myosins

Topics

• Amino Acid Sequence
• Base Sequence
• Blotting, Northern
• Blotting, Southern
• DNA, Fungal (genetics)
• Dictyostelium (genetics)
• Genes
• Genes, Fungal
• Molecular Sequence Data
• Myosin Subfragments
• Myosins (genetics)
• Peptide Fragments (genetics)
• Restriction Mapping
• Sequence Homology, Nucleic Acid