CCDC42 Localizes to Manchette, HTCA and Tail and Interacts With ODF1 and ODF2 in the Formation of the Male Germ Cell Cytoskeleton

Abstract

Terminal differentiation of male germ cells into functional spermatozoa requires shaping and condensation of the nucleus as well as the formation of sperm-specific structures. A transient microtubular structure, the manchette, is mandatory for sperm head shaping and the development of the connecting piece and the sperm tail. The connecting piece or head-to-tail coupling apparatus (HTCA) mediates the tight linkage of sperm head and tail causing decapitation and infertility when faulty. Using mice as the experimental model, several proteins have already been identified affecting the linkage complex, manchette or tail formation when missing. However, our current knowledge is far too rudimentary to even draft an interacting protein network. Depletion of the major outer dense fiber protein 1 (ODF1) mainly caused decapitation and male infertility but validated binding partners collaborating in the formation of sperm-specific structures are largely unknown. Amongst all candidate proteins affecting the HTCA when missing, the structural protein CCDC42 attracted our attention. The coiled-coil domain containing 42 (CCDC42) is important for HTCA and sperm tail formation but is otherwise largely uncharacterized. We show here that CCDC42 is expressed in spermatids and localizes to the manchette, the connecting piece and the tail. Beyond that, we show that CCDC42 is not restricted to male germ cells but is also expressed in somatic cells in which it localizes to the centrosome. Although centrosomal and sperm tail location seems to be irrespective of ODF1 we asked whether both proteins may form an interacting network in the male germ cell. We additionally considered ODF2, a prevalent protein involved in the formation of spermatid-specific cytoskeletal structures, as a putative binding partner. Our data depict for the first time the subcellular location of CCDC42 in spermatids and deepen our knowledge about the composition of the spermatid/sperm-specific structures. The presence of CCDC42 in the centrosome of somatic cells together with the obvious restricted male-specific phenotype when missing strongly argues for a compensatory function by other still unknown proteins most likely of the same family.

The WD40-protein CFAP52/WDR16 is a centrosome/basal body protein and localizes to the manchette and the flagellum in male germ cells

“…A similar distribution in the manchette and the sperm tail was observed for the outer dense fibre protein 1, ODF1 31 , posing the question whether the observed colocalization indicates interaction or interdependency. We, therefore, investigated CFAP52 localization in testicular sections using both wild-type as well as Odf1-deficient mice 28 .…”

“…Hook1 -depletion, furthermore, disrupted the tight connection between flagellum and nucleus causing sperm decapitation 26 . Sperm decapitation and male infertility were also observed when the outer dense fibre protein ODF1 or one of its interacting proteins centrosomal protein coiled-coil domain containing 42 (CCDC42) or the testis-specific SUN-domain protein SPAG4L/SUN5 were mutated 28 – 31 . SUN-domain proteins are integral nuclear membrane proteins and are part of the linker of nucleoskeleton and cytoskeleton (LINC) complex responsible for bridging the nuclear envelope and the cytoskeleton 32 .…”

Preliminary investigation of the function of hsa_circ_0049356 in nonobstructive azoospermia patients

“…Moretti et al suggested that TBL1XR1 interacts with SLY, which is closely associated with the master genes of spermatid transcriptional regulation and further modulated the chromatin remodelling process (Moretti et al., 2017). Contreras et al revealed that CCDC42 localises to spermatid manchette, and binds to the ODF1 and ODF2 proteins, which are required for the formation of cytoskeletal structures of sperm (Tapia Contreras & Hoyer‐Fender, 2019). Moreover, PRAME deletion in mice has been found to be associated with germ cell apoptosis and abnormal seminiferous tubules, suggesting its role in spermatogenesis (Lu et al., 2020).…”

Sperm Differentiation: The Role of Trafficking of Proteins

“…Additionally, SPERM1 transports UBQLN1 [174] and RANBP17 [175] in the manchette. The coiled-coil domain containing 42 (CCDC42) protein has been found to be enriched in the perinuclear ring and to colocalize with acetylated-tubulin in the manchette [176]. Ccdc42-mutant mice display defects in the manchette [177].…”

“…Ccdc42-mutant mice display defects in the manchette [177]. The molecular function of CCDC42 is unknown, but it was shown to interact with ODF1 and ODF2 [176]. Table 4.…”