The function of ENSG00000130413 (STK33, serine/threonine kinase 33) is as follows. Serine/threonine protein kinase required for spermatid differentiation and male fertility (PubMed:37146716, PubMed:38781365). Promotes sperm flagella assembly during spermatogenesis by mediating phosphorylation of fibrous sheath proteins AKAP3 and AKAP4 (By similarity). Also phosphorylates vimentin/VIM, thereby regulating the dynamic behavior of the intermediate filament cytoskeleton (By similarity). {ECO:0000250|UniProtKB:Q924X7, ECO:0000269|PubMed:37146716, ECO:0000269|PubMed:38781365}.