KIF5C: A new binding partner for protein kinase CK2 with a preference for the CK2α’ subunit

Abstract

Protein kinase CK2 is a highly conserved serine/threonine kinase that is ubiquitously expressed in eukaryotic cells. CK2 is a constitutively active tetrameric enzyme composed of two catalytic alpha and/or alpha'-subunits and two regulatory beta-subunits. There is increasing evidence that the individual subunits may have independent functions and that they are asymmetrically distributed inside the cell. To gain a better understanding of the functions of the individual subunits, we employed a yeast-two-hybrid screen with CK2alpha and CK2alpha'. We identified the motor neuron protein KIF5C as a new binding partner for CK2. The interaction found in the yeast-two-hybrid screen was confirmed by co-sedimentation analysis on a sucrose density gradient and by co-immunoprecipitation analysis. Pull-down experiments and surface plasmon resonance spectrometry revealed a direct binding of KIF5C to CK2alpha'. Co-localization studies with neuroblastoma cells, bone marrow and with primary neurons confirmed the biochemical analysis that KIF5C preferentially bound to CK2alpha'.

Protein kinase CK2 and new binding partners during spermatogenesis

“…Recently, we detected KIF5C as a new binding partner for the catalytic subunits of CK2 [19]. Here, we show that KIF5C was also expressed in spermatozoa.…”

“…In addition to Western Blot these antibodies were also used in immune histochemical analysis and immunofluorescence [21,22]. KIF5C was detected with the rabbit antibody #976, which was raised against a KIF5C-specific peptide with the amino acid sequence CDNTPIIDNIAPV [19]. A highly purified TNP1 protein was used to immunize a rabbit.…”

“…TNP1 was detected with a GST-specific rabbit serum in a dilution of 1:1,000. Rabbit antibody #976 [19] was used for the detection of KIF5C. After washing with PBS-Tween-20 with 1% dry milk, the membrane was incubated with the peroxidase-coupled secondary antibody in a dilution of 1:10,000 (anti-mouse) or 1:30,000 (antirabbit) for 1 h at room temperature.…”

“…The kinesin heavy chain protein KIF5C is expressed in brain, spinal cord [16], the retina [17], and also in spermatids [18]. We recently found that the KIF5C protein, at least in neurons, preferentially bound to CK2a 0 [19]. Here, we applied immunohistochemistry and immunogold labeling to examine the distribution of CK2 subunits and their interacting partners TNP1 and KIF5C in mouse testis.…”

Intrinsic disorder in the kinesin superfamily

“…The few ligands that have been shown to bind directly to kinesin motor domains, interact primarily with disordered loops, and are described as follows. The Kif5C motor domain binds casein kinase II (protein kinase CK2), which phosphorylates the disordered neck-linker at Thr338 (Schafer et al 2009). The Kif1Bα and Kif1C motors bind the Kif1 binding protein (KBP) in the vicinity of the disordered K-loop, and KBP facilitates the transport of mitochondria by these motors (Wozniak et al 2005).…”