6 - 8 dynein-dynactin complexes/kinesin
||Fu MM, Holzbaur EL. Integrated regulation of motor-driven organelle transport by scaffolding proteins. Trends Cell Biol. 2014 Oct24(10):564-74. doi: 10.1016/j.tcb.2014.05.002. p.565 caption to figure 1B & left column 2nd paragraphPubMed ID24953741
||A.G. Hendricks, et al. Motor coordination via a tug-of-war mechanism drives bidirectional vesicle transport Curr. Biol., 20 (2010), pp. 697–702 doi: 10.1016/j.cub.2010.02.058.PubMed ID20399099
||Quantitative immunoblotting of purified vesicles
||P.565 caption to figure 1B:" In the tug-of-war model, both kinesin and dynein–dynactin motors are bound to the cargo simultaneously. The cargo will move bidirectionally along the microtubule, depending on stochastic variations in the dominant motor type. Note that, for simplification, this figure only illustrates one dynein–dynactin complex per vesicle, but likely 6–8 dynein–dynactin complexes are on each vesicle to reach force balance with one kinesin." P.565 left column 2nd paragraph:"Experimental work in several systems supports this [tug-of-war] model. For example, late endosomes and lysosomes moving along neuronal axons exhibit bidirectional motility, characterized by short run length, either toward or away from the cell body, punctuated by frequent changes in direction. Quantitative immunoblotting of purified vesicles indicates that each organelle binds few (1–2) kinesin motors and a larger team (6–12) of dynein motors [primary source]. However, because kinesins generally exhibit high unitary stall forces (∼5–7 pN) whereas mammalian cytoplasmic dynein has a low unitary stall force (∼1 pN) [BNID 112209], these opposing motors are present near force balance on each organelle. The resulting stochastic tug-of-war between these relatively evenly matched motor teams is predicted to cause frequent directional switches and low net processivity [primary source]."