Kinesin-like protein KIF3B is a protein that in humans is encoded by the KIF3Bgene.[5][6] KIF3B is an N-type protein that complexes with two other kinesin proteins to form two-headed anterograde motors.[7] First, KIF3B forms a heterodimer with KIF3A (kinesin-like protein KIF3A); (KIF3A/3B), that is membrane-bound and has ATPase activity. Then KIFAP3 (KAP3, kinesin superfamily associated protein–3) binds to the tail domain to form a heterotrimeric motor.[7] This motor has a plus end-directed microtubule sliding activity that exhibits a velocity of ~0.3 μm/s a.[8] There are 14 kinesin protein families in the kinesin superfamily and KIF3B is part of the Kinesin-2 family, of kinesins that can all form heterotrimeric complexes.[9] Expression of the three motor subunits is ubiquitous. The KIG3A/3B/KAP3 motors can transport 90 to 160 nm in diameter organelles.[7]
The heterotrimeric KIF3B/KIF3A/KAP3 motor machinery functions in the intracellular transport of multiple different molecules such as β-catenin and MT1-MMP.[10][11] KIF3B activity has been implicated with various cellular processes such as intracellular movement of organelles, intraflagellar transport, chromosome movement during mitosis and meiosis, and cellular interaction with the extracellular matrix.[6][12][13]
KIF3B also regulates the interaction of cancer cells with the extracellular matrix (ECM), in particular the transport of MT1-MMP to the cancer cell front is essential for collagen fiber matrix realignment and degradation.[14][15]
^Jimbo T, Kawasaki Y, Koyama R, Sato R, Takada S, Haraguchi K, Akiyama T (April 2002). "Identification of a link between the tumour suppressor APC and the kinesin superfamily". Nature Cell Biology. 4 (4): 323–7. doi:10.1038/ncb779. PMID11912492. S2CID10745049.
Navarro E, Espinosa L, Adell T, Torà M, Berrozpe G, Real FX (July 1999). "Expressed sequence tag (EST) phenotyping of HT-29 cells: cloning of ser/thr protein kinase EMK1, kinesin KIF3B, and of transcripts that include Alu repeated elements". Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1450 (3): 254–64. doi:10.1016/S0167-4889(99)00051-8. PMID10395937.
Whitehead JL, Wang SY, Bost-Usinger L, Hoang E, Frazer KA, Burnside B (November 1999). "Photoreceptor localization of the KIF3A and KIF3B subunits of the heterotrimeric microtubule motor kinesin II in vertebrate retina". Experimental Eye Research. 69 (5): 491–503. doi:10.1006/exer.1999.0724. PMID10548469.
Jimbo T, Kawasaki Y, Koyama R, Sato R, Takada S, Haraguchi K, Akiyama T (April 2002). "Identification of a link between the tumour suppressor APC and the kinesin superfamily". Nature Cell Biology. 4 (4): 323–7. doi:10.1038/ncb779. PMID11912492. S2CID10745049.
