Google PageRank only reflects incoming links to your Hub so, no, your specific URL has no bearing on PageRank because it is the URL to your Hub and not a link to it.
I think you probably want to know if the URL can affect the search ranking of your Hub. The answer is yes, it can. How important a role it plays depends upon many things, such as your competition for search query results. You can read more about how this works in my Hub: http://hubpages.com/business/SEO-Tutorial-Guide...
Go to this section from the Table of Contents: III. A. 1. Keywords
Unless your URL is totally unrelated to the content of your Hub, don't worry about changing it and just change your Title and on-page optimization if you need to.
The only way to change the URL on HubPages is to unpublish the Hub and start over again with a new one.