Evidence for presence of hyaluronan binding protein on spermatozoa and its possible involvement in sperm function

Abstract

Hyaluronic acid, a major component of the extracellular matrix, plays an important role in the regulation of different cellular processes, e.g., locomotion, cell-cell interaction during morphogenesis, and differentiation. Distribution of hyaluronic acid with respect to the role of sperm hyaluronidase in sperm penetration and gamete interaction is well established. In order to elucidate this mechanism, in our current study we have identified and demonstrated, for the first time, the presence of a 68-kDa cell surface hyaluronic acid binding glycoprotein (HABP) in spermatozoa of different species (rat, mice, bull, and human) by immunoblot analysis and indirect immunofluorescence using the polyclonal antibodies raised against purified HABP. Furthermore, we were able to demonstrate a differential distribution of 68-kDa HA binding protein on the sperm head, midpiece, and tail of different species. To identify its role in sperm function, we observed its declining pattern during epididymal maturation and also the inhibition of sperm-oolemmal adherence by pretreatment of the sperms with anti-HABP antibodies. We have further observed its in vivo phosphorylation in motile spermatozoa. All our data clearly indicate that sperm hyaluronan binding protein may have a specific role in sperm maturation, motility, and fertilization processes.

Structural Flexibility of Multifunctional HABP1 May Be Important for Regulating Its Binding to Different Ligands

“…We established its role in cell adhesion and tumor invasion (8 -9) and sperm maturation and motility (10,11). The cDNA encoding hyaluronan-binding protein 1 has been cloned by immunoscreening the human skin fibroblast expression library, sequenced, and overexpressed (7).…”

Screening of Differentially Expressed Genes Related to Bladder Cancer and Functional Analysis with DNA Microarray

“…C1QBP/p32, which is also represented as synonyms of HABP1 (Hyaluronan Binding Protein 1) is one of hyaladherin implicated in cellular functions like adhesion and tumor invasion (Guptaand Datta, 1991), sperm maturity and motility (Ranganathan et al, 1994) and cellular signaling (Rao et al, 1996). It presents in human chromosome 17p12-13 (accession number NP_001203) and encodes a sialic acid containing a pro-protein sequence of 282 amino acids, consist of the first 73 amino acids which are cleaved off during protein mature procedure and the rest mature protein of 209 amino acids (Deband Datta, 1996).…”

Hyaluronic acid induced hyaluronic acid binding protein phosphorylation and inositol triphosphate formation in lymphocytes

“…The presence of two plasma membrane proteins of 37 kDa and 41 kDa, showing specific binding to this HA-binding protein have been demonstrated (9). Ranganathan et al, observed the in vivo phosphorylation of this protein in motile spermatozoa and described its role in sperm maturation, motility and fertility processes (10,11). In order to establish its role in lymphocyte signal tran_sduction, we studied the HA-induced signalling events namely, cell aggregation, total tyrosine phosphorylation, cytoskeletal protein phosphorylation and IP3 formation.…”