GSBS Student Publications

Title

Homology of the 74-kD cytoplasmic dynein subunit with a flagellar dynein polypeptide suggests an intracellular targeting function

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cell Biology

Date

9-1-1992

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Animals; Base Sequence; Blotting, Western; Brain; Cilia; Cytoplasm; DNA; Dynein ATPase; Flagella; Humans; Male; Molecular Sequence Data; RNA, Messenger; Rats; Rats, Inbred Strains; Sheep; Sperm Tail; Testis

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

In previous work we found cytoplasmic dynein to be a complex of two catalytic heavy chains and at least seven co-purifying polypeptides of unknown function. The most prominent of these is a 74-kD electrophoretic species which can be resolved as two to three bands by SDS-PAGE. We have now selected a series of overlapping rat brain cDNAs encoding the 74-kD species. The deduced sequence of a full-length cDNA predicts a 72,753 D polypeptide which includes the amino acid sequences of nine peptides determined by NH2-terminal microsequencing. PCR performed on first strand rat brain cDNA together with the sequence of a partially matching tryptic peptide indicated the existence of at least three isoforms of the 74-kD cytoplasmic dynein subunit. Comparison with known sequences revealed that the carboxyl-terminal half of the polypeptide is 26.4% identical and 47.7% similar to the product of the Chlamydomonas ODA6 gene, a 70-kD intermediate chain of flagellar outer arm dynein. Immunoblot analysis with a monoclonal antibody to the 74-kD species indicated a widespread tissue distribution, as expected for a cytoplasmic dynein subunit. Nonetheless, the antibody recognized a 67-kD species in ram sperm flagella and pig tracheal cilia, supporting the existence of distinct but related cytoplasmic and axonemal polypeptides in mammals. In view of evidence for a role for the ODA6 gene product in anchoring flagellar dynein to the A subfiber microtubule in the axoneme, we predict an analogous role for the 74-kD polypeptide, perhaps in mediating the interaction of cytoplasmic dynein with membranous organelles and kinetochores.

Rights and Permissions

Citation: J Cell Biol. 1992 Sep;118(5):1133-43.

Related Resources

Link to article in PubMed

Journal Title

The Journal of cell biology

PubMed ID

1387402