Puttaswamy Manjunath

TITLE

• Professor, Faculty of Medicine, University of Montreal

EDUCATION

• Postdoctorate, Montreal Institute for Clinical Research (1980-1984).
• Ph.D., University of Mysore, India (1980).

RESEARCH INTERESTS

• Biochemical characterization and physiological role(s) of proteins from the  male reproductive tract;
• Mechanism of sperm protection by egg yolk and milk.

SUMMARY

Biochemical characterization and physiological role(s) of proteins from the male reproductive tract:

In mammals, sperm emerging from the male reproductive tract are incapable of fertilizing egg; however, they acquire this ability during their journey in the female reproductive tract. 

This prerequisite conditioning is called capacitation and it is one of the key events that regulate fertility.  A part of this process involves loss or modification of surface components acquired by sperm during epididymal maturation and their contact with seminal plasma.  We have isolated and characterized a family of proteins from bovine seminal plasma (BSP proteins), which are added to sperm during ejaculation. 

Our studies have demonstrated that these proteins are essential for capacitation and are ubiquitous in mammals. Sequences homologous to BSP proteins have been identified in human and mouse genomes. Two homologous cDNA sequences in mouse and one in human have been cloned and their specific expression (mRNA) in epididymis has been shown. To study the functions, mouse and human BSP homologous proteins have been expressed in bacteria and purified. Further studies on these novel proteins may aid in the understanding of mechanisms involved in fertilization and identification of factors important for human fertility.

Mechanism of sperm protection by egg yolk and milk:

Over the past 60 years, egg-yolk and milk have been routinely used in both liquid semen extenders and those used to cryopreserve sperm.  However, the mechanism by which egg yolk and milk protect sperm during liquid storage or from freezing damage is unknown. 

Thus our laboratory is studying the mechanisms involved in sperm protection by milk and egg yolk.  We discovered that a group of phospholipid-binding proteins (PL-BP), which are detrimental to sperm, are added to sperm at ejaculation.  Interestingly, these detrimental factors bind caseins/whey proteins and low-density lipoproteins found in milk and egg yolk respectively. This interaction appears to reduce lipid loss from the sperm membrane, thereby preventing membrane damage during storage and preserving the sperm functions (motility, viability and acrosomal integrity). 

In future studies we would like to further characterize the interaction between PL-BPs and milk components and develop novel sperm storage medium for commercial application

RESEARCH TEAM

Research assistant:

• Isabelle Thérien, Ph.D. 

Ph.D. Students:

• Geneviève Plante 
• Marie-France Lusignan

Postdoctorate:

• Prashanth S. Jois

DISTINCTIONS AND ACHIEVEMENTS

• Research Grant, FRSQ (1984-1993).
• CIHR-IHDCYH Lectureship, Child and Reproductive Health Research (2006).
• CIHR-IHDCYH Lectureship, Institute Community Support Award (2008).

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selected papers

Jois PS, Manjunath P. (2010)  The N-terminal part of Binder of sperm 5 (BSP5), which promotes sperm capacitation in bovine species is intrinsically disordered.   Biochem Biophys Res Commun. Mar 21.

Lefebvre J, Boileau G, Manjunath P. (2009)  Recombinant expression and affinity purification of a novel epididymal human sperm-binding protein, BSPH1. Mol Hum Reprod. 15(2):105-14.

Manjunath P, Lefebvre J, Jois PS, Fan J, Wright MW.  (2009) New nomenclature for mammalian BSP genes.  Biol Reprod. 80(3):394-7.

Lassiseraye D, Courtemanche L, Bergeron A, Manjunath P, and Lafleur M. (2008) Binding of bovine seminal plasma protein BSP-A1/A2 to model membranes:  Lipid specificity and Effect of the temperature.  Biochem. Biophys. Acta 1778: 502-513.

Manjunath, P., Bergeron, A., Lefebvre, J. and Fan, J. (2007) Seminal plasma proteins: functions and interaction with protective agents during semen preservation. Rolden, E.R.S and Gomendio, M (eds). Society for Reproduction and Fertility Supplement 65: 217-228. Nottingham University Press.

Bergeron, A., Brindle, Y., Blondin P., Manjunath, P. (2007) Milk caseins decreased the binding of major bovine seminal plasma proteins to sperm and prevend lipid loss from the sperm membrane during sperm storage. Biol. Reprod. 77: 120-126.

Lefebvre, J., Fan, J., Chevalier, S., Sullivan, R., Carmona, E., Manjunath, P. (2007) Genomic structure and tissue-specific expression of human and mouse genes encoding homologues of the major bovine seminal plasma proteins. Mol Hum Reprod. 13: 45-53.

Lusignan, M-F., Bergeron, A., Crete, M-H., Lazure, C., Manjunath, P. (2007) Induction of Epididymal Boar Sperm Capacitation by pB1 and BSP-A1/-A2 Proteins, Members of the BSP Protein Family. Biol Reprod. 76: 424-432.

Bergeron, A., Manjunath, P. New insights towards understanding the mechanisms of sperm protection by egg yolk and milk. (2006) Mol Reprod Dev. 73:1338-1344.

Fan, J., Lefebvre, J., Manjunath, P. (2006) Bovine seminal plasma proteins and their relatives: A new expanding superfamily in mammals. Gene. 375:63-74.

Complete list of Dr Manjunath's publications (PubMed)

ADDITIONAL INFORMATION

Grants

• Canadian Institutes of Health Research
• Natural Sciences and Engineering Research Council of Canada

Grants obtained by students of Dr. Manjunath (december 2009): 

• Geneviève Plante : The Alexander Graham Bell Canada Graduate Scholarships-Ph.D. (2010-2013)
• Geneviève Plante : The Alexander Graham Bell Canada Graduate Scholarships-M.Sc. (2009-2010)
• Geneviève Plante : MSc scholarships FRSQ (2009-2011)
• Geneviève Plante : bourse d’accès direct au doctorat FESP, Université de Montréal  (2009)
• Geneviève Plante : Research Trainee Travel Award-CIHR-IHDCYH (2010)
• Marie-France Lusignan : Award FQRNT (2008-2009)
• Marie-France Lusignan : bourse de fin d’études doctorales de la FES, Université de Montréal (2009-2010)
• Marie-France Lusignan : Travel Award NIH et RQR (2010)
• Hanieh Bagheri: Summer Internship Award 2009, NSERC

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