As far as copyright goes, no. Titles are not copyrightable, nor generally are short phrases, slogans, mottoes or names - although any of these could potentially be trademark-protected.
The main advantage to having a title that is different from anyone else's is so no one gets your work confused with (or compared to) another work of the same name. A work that is unique deserves a unique name.
As a note, your screenplay was copyrighted as soon as you wrote it. Copyright is automatic once a creative and original work is fixed in a tangible form.
Registration of a copyrighted work is not required, whether it is with the Writer's Guild or with the Copyright Office. But in order to sue for infringement in federal court, registration with the U.S. Copyright Office is necessary.
Registration with the U.S. Copyright Office gives you proof of the date of registration, which can translate to proof of the date you created your work, which can be important if you believe your work has been infringed. Someone who has registered their work with the U.S. Copyright Office is the presumptive copyright owner, this even if an unregistered work was created first (although, with sufficient evidence, this presumption of ownership can potentially be overcome).
Registration with the Copyright Office works as well to provide public notice to others that your work is protected by copyright, which makes it harder for any infringer to claim "innocent" infringement (which, when used successfully as a defense to a suit, can mitigate the amount of damages awarded). Registration with the U.S. Copyright Office can also entitle you to statutory damages (depending on when the work is registered, when the work is published, when the work is infringed), instead of being limited to actual damages suffered or to the profits made by the infringer (if any).
But, to work my way back to your question, you can use the title "King of Venus" and the author of the novelette can also use the title "King of Venus," as long as "King of Venus" is not being used as a trademark already by someone else. Neither of you would be violating the copyright of the other. This doesn't mean that the author of the novelette may not decide to sue you over your use of "King of Venus" anyway - because anyone can sue anyone else for pretty much any reason at all - but a copyright infringement suit that is based only on the titles of your work and his work being the same should not have legal merit.
It is always wise and recommended to have any work intended for publication reviewed by an attorney well-versed in publishing law prior to publication. This review can help you identify legal issues in advance so that you can address them. Insurance is good to have, as well.
