Kinesin-like protein KIF3B is aprotein that in humans is encoded by theKIF3Bgene.[5][6] KIF3B is an N-type protein that complexes with two otherkinesin 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 hasATPase activity. ThenKIFAP3 (KAP3, kinesin superfamily associated protein–3) binds to the tail domain to form a heterotrimeric motor.[7] This motor has a plus end-directedmicrotubule sliding activity that exhibits a velocity of ~0.3 μm/s a.[8] There are 14 kinesin protein families in thekinesin superfamily and KIF3B is part of the Kinesin-2 family of kinesins that form heterotrimeric or homodimeric complexes.[9][10] Expression of the three motor subunits of heterotrimeric kinesin-2 is ubiquitous. The KIF3A/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.[11][12] KIF3B activity has been implicated with various cellular processes such as intracellular movement oforganelles,intraflagellar transport, chromosome movement duringmitosis andmeiosis, and cellular interaction with the extracellular matrix.[6][13][14]
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.[15][16]
^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.
