Kif5B and Kifc1 Interact and Are Required for Motility and Fission of Early Endocytic Vesicles in Mouse Liver

Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Molecular Biology of the Cell (Impact Factor: 4.47). 06/2007; 18(5):1839-49. DOI: 10.1091/mbc.E06-06-0524
Source: PubMed


Early endocytic vesicles loaded with Texas Red asialoorosomucoid were prepared from mouse liver. These vesicles bound to microtubules in vitro, and upon ATP addition, they moved bidirectionally, frequently undergoing fission into two daughter vesicles. There was no effect of vanadate (inhibitor of dynein) on motility, whereas 5'-adenylylimido-diphosphate (kinesin inhibitor) was highly inhibitory. Studies with specific antibodies confirmed that dynein was not associated with these vesicles and that Kif5B and the minus-end kinesin Kifc1 mediated their plus- and minus-end motility, respectively. More than 90% of vesicles associated with Kifc1 also contained Kif5B, and inhibition of Kifc1 with antibody resulted in enhancement of plus-end-directed motility. There was reduced vesicle fission when either Kifc1 or Kif5B activity was inhibited by antibody, indicating that the opposing forces resulting from activity of both motors are required for fission to occur. Immunoprecipitation of native Kif5B by FLAG antibody after expression of FLAG-Kifc1 in 293T cells indicates that these two motors can interact with each other. Whether they interact directly or through a complex of potential regulatory proteins will need to be clarified in future studies. However, the present study shows that coordinated activity of these kinesins is essential for motility and processing of early endocytic vesicles.

14 Reads
  • Source
    • "RE Rip11/FIP5 [133] LE/lysosomes Unknown [65] [109] EE tubules; SNX4 Unknown [58] Kinesin-3 KIF1B␤ LE/lysosomes Unknown [115] [135] KIF13A RE Rab11 [132] KIF16B EE/RE PtdIns-3P [107] [109] Khc-73 (D. melanogaster) EE (Unknown) [106] Kinesin-13 KIF2␤ LE/lysosomes Unknown [116] Kinesin-14 KIFC1 EE Unknown [67] KIFC2 EE Unknown [66] Dynein/dynactin LIC1 LE/lysosomes RILP [63] LIC1/2 RE FIP3 [130] [131] LIC1 RE Rab4 [90] LIC (D. rerio) LE/lysosomes JIP3 (in neurons) [100] IC LE/lysosomes Snapin [102] LC8 EE tubules; SNX4 Kibra [129] "
    [Show abstract] [Hide abstract]
    ABSTRACT: The endocytic pathway is essential for processes that define how cells interact with their environment, including receptor signalling, cell adhesion and migration, pathogen entry, membrane protein turnover and nutrient uptake. The spatial organisation of endocytic trafficking requires motor proteins that tether membranes or transport them along the actin and microtubule cytoskeletons. Microtubules, actin filaments and motor proteins also provide force to deform and assist in the scission of membranes, thereby facilitating endosomal sorting and the generation of transport intermediates.
    Seminars in Cell and Developmental Biology 01/2014; · 6.27 Impact Factor
  • Source
    • "So in other word, the function of KIFC1 in S. maindroni is similar to that in mammals . As we know, the KIFC1 protein has different roles in various tissues, such as it is essential in the fusion of vesicles in the lung of rat (Nath et al., 2007). kifc1 mRNA expressed in different tissue. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we investigated the gene sequence and characteristic of kifc1 in Sepiella maindroni through PCR and RACE technology. Our research aimed particularly at the spatio-temporal expression pattern of kifc1 in the developmental testis through in situ hybridization. The particular role of kifc1 in the spermatogenesis of S. maindroni was our particular interest. Based on multiple protein sequence alignments of KIFC1 homologues, kifc1 gene from the testis of S. maindroni was identified, which consisted of 2432bp including a 2109 in-frame ORF corresponding to 703 continuous amino acids. The encoded polypeptide shared highest similarity with Octopus tankahkeei. Through the prediction of the secondary and tertiary structure, the motor domain of KIFC1 was conserved at the C-terminal, having putative ATP-binding and microtubule-binding motifs, while the N-terminal was more specific to bind various cargoes for cellular events. The stalk domain connecting between the C-terminal and N-terminal, determined the direction of movement. According to RT-PCR results, the kifc1 gene is not tissue-specific, commonly detected in different tissues, for example, testis, liver, stomach, muscle, caecum and gills. Through an in situ hybridization method, the expression pattern of KIFC1 protein mimics in the spermatogenesis of S. maindroni. During the primary stage of the spermatogenesis, the kifc1 mRNA signal was barely detectable. At the early spermatids, the signal started to be present. With the elongation of spermatids, the signals increased substantially. It peaked and gathered around the acrosome area when the spermatids began to transform to spindle shape. As the spermatids developed into mature sperm, the signal vanished. In summary, the expression of kfic1 at specific stages during spermiogenesis and its distribution shed light on the potential functions of this motor in major cytological transformations. The KIFC1 homologue may provide a direct shaping force to the nucleus or influence the shaping process through indirect regulation.
    Gene 09/2013; 532(1). DOI:10.1016/j.gene.2013.09.008 · 2.14 Impact Factor
  • Source
    • "We define dynein-1 and kinesin-1 as motors for SNX1- and SNX8-labelled membranes and dynein-1 and kinesin-2 as motors for SNX4-labelled endosomes. All of these motors have been shown previously to mediate endosomal functions in many systems (Aniento et al., 1993; Brown et al., 2005; Nath et al., 2007; Schuster et al., 2011a). Our data highlight a specificity of motor coupling with respect to domain organization and motility of early endosomes. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Many microtubule motors have been shown to couple to endosomal membranes. These motors include dynein as well as many different kinesin family members. Sorting nexins (SNXs) are central to the organization and function of endosomes. These proteins can actively shape endosomal membranes and couple directly or indirectly to the minus-end microtubule motor dynein. Motor proteins acting on endosomes drive their motility, dictate their morphology and impact on cargo segregation. We have used well-characterized members of the sorting nexin family to elucidate motor coupling using high resolution light microscopy coupled with depletion of specific microtubule motors. Endosomal domains labelled with sorting nexins 1, 4, and 8 (SNX1, SNX4, SNX8) couple to discrete combinations of dynein and kinesin motors. These specific combinations govern the structure and motility of each SNX-coated membrane as well as the segregation of distinct functional endosomal subdomains. Together our data show that these key features of endosome dynamics are governed by the same set of opposing microtubule motors. Thus, microtubule motors help to define the mosaic layout of endosomes that underpins cargo sorting.
    Journal of Cell Science 04/2013; 126(11). DOI:10.1242/jcs.122317 · 5.43 Impact Factor
Show more

Preview (2 Sources)

14 Reads
Available from