Molecular evaluation of two major human sperm fibrous sheath proteins, pro-hAKAP82 and hAKAP82, in stump tail sperm

Objective: To determine whether mutations in the pro-hAKAP82 gene and the r esulting pro-hAKAP82 and hAKAP82 proteins were associated with the infertil ity seen in a patient with stump tail I sperm. Design: Case report. Setting: Academic research and teaching environment, tertiary care hospital . Patient(s): A single, infertile Caucasian male diagnosed with essentially 1 00% stump tail sperm. Intervention(s): None. Main Outcome Measure(s): Electrophoresis, silver staining, and immunoblotti ng of patient and control sperm proteins; RII (type II regulatory subunit o f protein kinase-A) overlay assay of patient and control sperm proteins, pa rtial DNA sequence analysis of patient's pro-hAKAP82 gene; indirect immunof luorescence and immunogold electron microscopy of patient and control sperm . Result(s): No significant abnormalities in the size or amount of pro-hAKAP8 2 and hAKAP82 or in the ability of these proteins to bind the regulatory su bunit of protein kinase-A were identified in the patient's sperm. Partial s equence analysis of the patient's pro-hAKAP82 gene was identical to the pub lished normal sequence. Indirect immunofluorescence and immunoelectron micr oscopy of sperm localized pro-hAKAP82/hAKAP82 to the sperm flagellum and de monstrated that the proteins were present in a disorganized, amorphous regi on, which apparently represented the fibrous sheath. Conclusion(s): These results suggest that, although pro-hAKAP82 and hAKAP82 localize to the correct structural component of the flagellum and are not directly responsible for the stump tail phenotype, they are unable to assem ble normally into the fibrous sheath. Although this study did not identify abnormalities in the pro-hAKAP82 gene or its resulting proteins in a patien t with stump tail sperm, several regions of the gene and protein remain to be examined. (C) 2001 by American Society for Reproductive Medicine.