Abstract
Background: Human serpin gene SERPINH1 encodes for a non-inhibitory serpin shock protein 47kDa (HSP47) a client-specific chaperone, which is a hallmark in the collagen biosynthesis. Till today, there is no comprehensive study on the protein network for human HSP47. Thus the current study aimed at studying the pathway and expression patterns observed in collagen-specific chaperone, HSP47 in relation to cancer.

Methodology: The study used online database STRING 10 (website: http://version10a.string-db.org (7)) in finding putative protein interaction partners of human HSP47. Also, database HMMER3 (www.hmmer.org/) with Pfam 32.0 (Sept 2018) dataset was used in identifying Pfam protein domains from proteins interacting with HSP47. The db DEPC 3.0, was used for evaluation of expression patterns of HSP47 in different cancer. Further three online resources namely, human protein atlas (HPA, https://www.proteinatlas.org/), genotype-tissue expression (GTEx https://gtexportal.org) and FANTOM5 project (http://fantom.gsc.riken.jp/5/) was used to examine HSP47 expression in normal human tissues.

Results: Upon constructing protein interactive map of human HSP47, the study found that a set of molecular chaperones as interaction partners of HSP47, which included two copies each of cAMP response element binding (CREB) binding proteins, HSP27, HSP40, HSP70, HSP90, ubiquitin proteins and one copy each of cartilage associated protein (CRTAP), HSPH1, HSBP1, FK506-binding protein 4 (FKBP4), kruppel-like factor (KLF13), peptidyl-prolyl isomerase PIPB and Prolyl 4-hydroxylase beta subunit (P4HB).

Conclusion: The study found a cocktail of different chaperones interacting with HSP47, originated at different time points from prokaryotes to eukaryotes. Overall, the study was successful in finding HSP47 expression patterns among several normal tissues using three different publicly available datasets. It also assessed the expression pattern of HSP47 in human cancer types. These findings will encourage further studies focusing on the role of HSP47 in human diseases.

Key words: HSP47, SERPINH1, protein-protein interaction, cancer, expression patterns