RGD Reference Report - Interactions of proteases, protease inhibitors, and the beta1 integrin/laminin gamma3 protein complex in the regulation of ectoplasmic specialization dynamics in the rat testis. - Rat Genome Database

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Interactions of proteases, protease inhibitors, and the beta1 integrin/laminin gamma3 protein complex in the regulation of ectoplasmic specialization dynamics in the rat testis.

Authors: Siu, MK  Cheng, CY 
Citation: Siu MK and Cheng CY, Biol Reprod. 2004 Apr;70(4):945-64. Epub 2003 Nov 26.
RGD ID: 1582607
Pubmed: PMID:14645107   (View Abstract at PubMed)
DOI: DOI:10.1095/biolreprod.103.023606   (Journal Full-text)

During spermatogenesis, developing germ cells migrate progressively across the seminiferous epithelium. This event requires extensive restructuring of cell-cell actin-based adherens junctions (AJs), such as the ectoplasmic specialization (ES, a testis-specific AJ type), between Sertoli cells and elongating/elongate spermatids. It was postulated that proteases and protease inhibitors worked in a yin-yang relationship to regulate these events. If this is true, then it is anticipated that both proteases and protease inhibitors are found at the ES. Indeed, matrix metalloprotease (MMP)-2, membrane-type 1 (MT1)-MMP and their inhibitor, tissue-inhibitor of metalloproteases (TIMP)-2, were shown to localize at the apical ES. In order to identify the putative MMP substrate as well as the unknown binding ligand for alpha6beta1 integrin in the ES, immunofluorescent microscopy coupled with immunoprecipitation techniques were used to demonstrate that laminin gamma3, largely a germ cell product, was present at the apical ES and could form a bona fide complex with beta1-integrin. Furthermore, the structural interactions of MMP-2 and MT1-MMP with laminin gamma3 and beta1-integrin, but not with N-cadherin or nectin-3, have implicated the crucial role of MMP-2/MT1-MMP in the regulation of integrin/laminin-based ES dynamics. Using an in vivo model to study AJ dynamics where adult rats were treated with 1-(2,4-dichlorobenzyl)-indazole-3-carbohydrazide (AF-2364) to disrupt Sertoli-germ cell adhesive function, an induction of active MMP-2, active MT1-MMP and TIMP-2 but not active MMP-9 was detected between 0.5 and 8 h after AF-2364 treatment. This time frame coincided with the depletion of elongating/elongate spermatids from the epithelium, illustrating the synergistic relationships between MMP-2, MT1-MMP, and TIMP-2 in AJ disassembly. Perhaps the most important of all, the use of a specific MMP-2 and MMP-9 inhibitor, (2R)-2-[(4-biphenylylsulfonyl)amino]-3-phenylpropionic acid, could effectively delay the AF-2364-induced elongating/elongate spermatid loss from the epithelium, demonstrating the pivotal role of MMP-2 activation in ES disassembly. Collectively, these studies illustrate that the beta1-integrin/laminin gamma3 complex is a putative ES-structural protein complex, which is regulated, at least in part, by the activation of MMP-2 involving MT1-MMP and TIMP-2 at the apical ES. The net result of this interaction likely regulates germ cell movement in the seminiferous epithelium.



Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
Mmp2Ratnegative regulation of cell adhesion  IDA  RGD 

Objects Annotated

Genes (Rattus norvegicus)
Mmp2  (matrix metallopeptidase 2)


Additional Information