THE HUMAN CYSTEINE-RICH SECRETORY PROTEIN (CRISP) FAMILY PRIMARY STRUCTURE AND TISSUE DISTRIBUTION OF CRISP-1, CRISP-2 AND CRISP-3

We report the isolation and characterisation of cDNAs encoding three d ifferent, human members of the cysteine-rich secretory protein (CRISP) family. The novel CRISP-1 exists in five cDNA subtypes differing by t he presence or absence of a stretch coding for a C-terminal cysteine-r ich domain so far found in all members of the family, and by the lengt h of their 3'-untranslated region. CRISP-2 cDNA corresponds to the pre viously described TPX1 form, with so far unreported 5'-untranslated se quence heterogeneities while CRISP-3 cDNA codes for a new, unique prot ein. Northern blot analysis of various human organs indicates that CRI SP-1 transcripts are epididymis-specific whereas CRISP-UTPX1 transcrip ts are detected mainly in the testis and also in the epididymis. CRISP -3 transcripts are more widely distributed and found predominantly in the salivary gland, pancreas and prostate, and in less abundance in th e epididymis, ovary, thymus and colon. A protein reacting with an anti -mouse CRISP-1 antibody was isolated from human epididymal extracts an d N-terminal sequencing revealed that it corresponded to the CRISP-1 c DNA we have isolated. In contrast to findings on its rat counterpart e pididymal protein DE/acidic epididymal glycoprotein (AEG), no signific ant association of CRISP-1 with human spermatozoa was observed.