hook protein

{{Short description|Family of evolutionarily related proteins}}

{{Pfam_box

| Symbol = HOOK

| Name = HOOK protein

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| Pfam= PF05622

| InterPro= IPR008636

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| OPM family=

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HOOK is a family of evolutionarily related proteins. This family consists of several HOOK1, 2 and 3 proteins from different eukaryotic organisms. The different members of the human gene family are HOOK1, HOOK2 and HOOK3. Different domains have been identified in the three human HOOK proteins, and it was demonstrated that the highly conserved N-terminal domain mediates attachment to microtubules, whereas the central coiled coil motif mediates homodimerisation and the more divergent C-terminal domains are involved in binding to specific organelles (organelle-binding domains). It has been demonstrated that endogenous HOOK3 binds to Golgi membranes,{{cite journal |vauthors=Kramer H, Liu X, Walenta JH, Didier AJ |title=The Golgi-associated hook3 protein is a member of a novel family of microtubule-binding proteins |journal=J. Cell Biol. |volume=152 |issue=5 |pages=923–934 |year=2001 |pmid=11238449 |doi=10.1083/jcb.152.5.923 |pmc=2198811}} whereas both HOOK1 and HOOK2 are localised to discrete but unidentified cellular structures. In mice the Hook1 gene is predominantly expressed in the testis. Hook1 function is necessary for the correct positioning of microtubular structures within the haploid germ cell. Disruption of Hook1 function in mice causes abnormal sperm head shape and fragile attachment of the flagellum to the sperm head.{{cite journal |vauthors=Engel W, Dixkens C, Neesen J, Burfeind P, Mendoza-lujambio I, Meinhardt A, Hoyer-fender S |title=The Hook1 gene is non-functional in the abnormal spermatozoon head shape (azh) mutant mouse |journal=Hum. Mol. Genet. |volume=11 |issue=14 |pages=1647–1658 |year=2002 |pmid=12075009 |doi=10.1093/hmg/11.14.1647|doi-access=free |citeseerx=10.1.1.490.653 }}