Kinesin is responsible for centrifugal movement of pigment granules in melanophores.

Abstract

Kinesin is a mechanochemical ATPase that induces translocation of latex beads along microtubules and microtubule gliding on a glass surface. This protein is thought to be a motor for the movement of membranous organelles in cells. Recently Hollenbeck and Swanson [Hollenbeck, P. J. & Swanson, J. A. (1990) Nature (London) 346, [864][865][866] showed that kinesin is involved in the positioning of tubular Iysosomes in macrophages. However, the role of this protein in the movement of organelles was not yet clear. We used a polyclonal antibody against the kinesin heavy chain that inhibited kinesindependent microtubule gliding in vitro to study the role of kinesin in the movement of pigment granules in melanophores of the teleost black tetra (Gymnocorymbus ternetzi). Microinjection of the antibody into cultured melanophores did not produce any specific effect on the aggregation o pigment granules in melanophores, but it did result in a strong dosedependent inhibition of the dispersion. Immunoblotting of melanophore extracts showed that the kinesin antibody reacted in these cells with a single protein component with a molecular mass of 135 kDa. Thus, kinesin is responsible for the movement of pigment granules from the center to the periphery of the melanophore.

Microtubule-dependent control of cell shape and pseudopodial activity is inhibited by the antibody to kinesin motor domain.

“…Indeed, we found that mitochondria collapsed to the cell center after the injection of antibody HD. Thus, positioning of mitochondria in fibroblasts, like positioning of lysosomes in macrophages (Hollenbeck and Swanson, 1990) and melanosomes in melanophores (Rodionov et al, 1991) depends on the functions of kinesin or related proteins recognized by our antibody. An attractive explanation of our results is that antibody injections selectively switched off motor(s) which directed mitochondria toward the cell periphery leaving unaffected a translocator of the opposite polarity that supported the transport of mitochondria toward cell center.…”

“…This antibody has already shown to interfere with a number of microtubnle motor functions, i.e., maintaining coalignment of intermediate vimentin filaments with microtubules in 1036 fibroblasts (Gyoeva and Gelfand, 1991) as well as centrifugal transport of pigment granules in fish melanophores (Rodionov et al, 1991). To check whether this antibody affected the intracellular transport of membranous organelles in fibroblasts as well, we analyzed the distribution of mitochondria in the cells in- jected with the antibody.…”

“…melanogaster kinesin heavy chain (antibody HD) was produced in rabbit and purified as described previously (Rodionov et al, 1991). For control experiments, IgG were purified from the preimmune serum by chromatography on protein A-Superose column (Pharmacia Diagnostics Inc., Fairfield, N J).…”

“…Microinjection was performed as described previously (Rodionov et al, 1991) with micromanipulator (Carl Zeiss, Inc., Thomwood, NY) and 5242 Eppendorf microinjector using an ICM-405 inverted microscope (Carl Zeiss, Inc.) with 32x long working distance phase 1 lens. Cells were injected with glass micropipettes made from 1.2 mm OD capillaries containing internal filaments to aid loading (World Precision InsU'uments, Inc., Sarasota, FL).…”

Self-organized optical device driven by motor proteins

“…When cytoplasmic dynein (a minus end-directed motor) is activated, the pigment granules are transported to and concentrated at the center of the cell, and the melanophore becomes transparent. In contrast, activation of kinesin II (a plus end-directed motor) induces dispersion of the pigments, which darkens the melanophore (19)(20)(21) (Fig. 1 C-F and Movie S1).…”