Differential expression of lysosomal associated membrane protein (LAMP-1) during mammalian spermiogenesis

Moreno, RD

Abstract

The mammalian acrosome is a secretory vesicle of mature sperms that plays an important role in fertilization. Recent evidence had pointed out that some components found at endosomes in somatic cells are associated with the developing acrosome during the early steps of spermiogenesis. Moreover, the mammalian acrosome contains many enzymes found within lysosomes in somatic cells. In this work, we studied the dynamics of some components of the endosome/lysosome system, as a way to understand the complex membrane trafficking circuit established during spermatogenesis. We show that the cation independent-mannose-6phosphate receptor (CI-MPR) is transiently expressed in the cytoplasm of mid-stage spermatids (steps 511). On the other hand, ?-adaptin, an adaptor molecule of a complex involved in trafficking from the Golgi to lysosomes, was expressed in cytoplasmic vesicles only in pachytene and Cap-phase spermatids (steps 1-5). Our major finding is that the lysosomal protein LAMP-1 is differentially expressed during spermiogenesis. LAMP-1 appears late in spermatogenesis (Acrosome-phase) contrasting with LAMP-2, which is present throughout the complete process. Both proteins appear to be associated with cytoplasmic vesicles and not with the developing acrosome. None of the studied proteins is present in epididymal spermatozoa. Our results suggest that the CI-MPR could be involved in membrane trafficking and/or acrosomal shaping during spermiogenesis. © 2003 Wiley-Liss, Inc.

Más información

Título según WOS: Differential expression of lysosomal associated membrane protein (LAMP-1) during mammalian spermiogenesis
Título según SCOPUS: Differential expression of lysosomal associated membrane protein (LAMP-1) during mammalian spermiogenesis
Título de la Revista: MOLECULAR REPRODUCTION AND DEVELOPMENT
Volumen: 66
Número: 2
Editorial: Wiley
Fecha de publicación: 2003
Página de inicio: 202
Página final: 209
Idioma: English
URL: http://doi.wiley.com/10.1002/mrd.10342
DOI:

10.1002/mrd.10342

Notas: ISI, SCOPUS