Cytoplasmic dynein 1 is a multi-protein intracellular motor essential for mediating several mitotic functions, including the establishment of proper spindle orientation. The functional relevance and mechanistic distinctions between two discrete dynein subpopulations distinguished only by Light Intermediate Chain (LIC) homologues, LIC1 and LIC2 is unknown during mitosis. Here, we identify LIC2-d...

The spindle checkpoint generates a "wait anaphase" signal at unattached kinetochores to prevent premature anaphase onset. Kinetochore-localized dynein is thought to silence the checkpoint by transporting checkpoint proteins from microtubule-attached kinetochores to spindle poles. Throughout metazoans, dynein recruitment to kinetochores requires the protein Spindly. Here, we identify a conserved...

Overlapping cDNA clones encoding the heavy chain of rat brain cytoplasmic dynein have been isolated. The isolated cDNA clones contain an open reading frame of 13,932 bp encoding 4644 aa (M(r), 532,213). The deduced protein sequence of the heavy chain of rat brain dynein shows significant similarity to sea urchin flagellar beta-dynein (27.0% identical) and to Dictyostelium cytoplasmic dynein (53...

Polyclonal antibodies have been raised against four 16 residue peptides with sequences taken from the C-terminal quarter of the human cytoplasmic dynein heavy chain. The sites are downstream from a known microtubule-binding domain associated with the "stalk" that protrudes from the motor domain. The antisera were assayed using bacterially expressed proteins with amino acid sequences taken from ...

Dynein is a minus-end-directed microtubule motor important for mitotic spindle positioning. In budding yeast, dynein activity is restricted to anaphase when the nucleus enters the bud neck, yet the nature of the underlying regulatory mechanism is not known. Here, the microtubule-associated protein She1p is identified as a novel regulator of dynein activity. In she1 Delta cells, dynein is activa...

In Paramecium tetraurelia, cyclic nucleotides are important physiological second messengers that could regulate dynein mechanochemistry by phosphorylation. A 29-kDa polypeptide that is phosphorylated in a cAMP- and Ca(2+)-sensitive manner in permeabilized cells and isolated axonemes is the only significant phosphorylated moiety that consistently copurifies with 22S dynein from paramecium cilia....

Previously, a 29-kD axonemal polypeptide (p29) that copurifies with 22S dynein has been shown to be phosphorylated in a cAMP- and Ca(2+)-sensitive manner, consistent with a role for this molecule in the signal transduction cascade leading to fast forward swimming in Paramecium tetraurelia (Hamasaki, T., K. Barkalow, J. Richmond, and P. Satir. 1991. Proc. Natl. Acad. Sci. USA. 88:7912-7922). Thi...

Cytoplasmic dynein is a microtubule-dependent motor protein that functions in mitotic cells during centrosome separation, metaphase chromosome congression, anaphase spindle elongation, and chromosome segregation. Dynein is also utilized during interphase for vesicle transport and organelle positioning. While numerous cellular processes require cytoplasmic dynein, the mechanisms that target and ...

Nudel and Lis1 appear to regulate cytoplasmic dynein in neuronal migration and mitosis through direct interactions. However, whether or not they regulate other functions of dynein remains elusive. Herein, overexpression of a Nudel mutant defective in association with either Lis1 or dynein heavy chain is shown to cause dispersions of membranous organelles whose trafficking depends on dynein. In ...

Effects of an antiserum against native dynein 1 from sperm flagella of the sea urchin Strongylocentrotus purpuratus were compared with effects of an antiserum previously obtained against an ATPase-active tryptic fragment (fragment 1A) of dynein 1 from sperm flagella of the sea urchin, Anthocidaris crassispina. Both antisera precipitate dynein 1 and do not precipitate dynein 2. Only the fragment...